Orion and Sirius the Dog Star

In late August and early September, look for a hint of the changing season in the predawn sky: Orion the Hunter and Sirius the Dog Star. The very noticeable constellation Orion the Hunter rises before dawn at this time of year, recognizable for the short straight line of three stars that make up Orion’s Belt. And the sky’s brightest star Sirius – sometimes called the Dog Star because it’s part of the constellation Canis Major the Greater Dog – follows Orion into the sky as the predawn darkness gives way to dawn.

Have you noticed a very bright, madly twinkling star in early morning sky? Many do – around the world – at this time of year. That star is Sirius. It’s so bright that, when it’s low in the sky, it shines with glints of red and flashes of blue – very noticeable!

Orion and the nearby star Sirius will become visible in the evening by northern winter (or southern summer). But presently the Hunter and the Dog Star lord over the sky at dawn’s first light.

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Matthew Chin in Hong Kong caught this photo of the stars and constellations that we in the Northern Hemisphere associate with winter – in late July, 2014. In late August – a full month later – all of these stars will have shifted higher in the east before sunrise. By December, they’ll be ascending in the east in the evening!

Orion was low in the west after sunset around March and April. By June of each year, this constellation lies behind the sun as seen from Earth. Orion only returned to visibility in Earth’s sky about a month ago (see image above). When a constellation becomes visible again, after being behind the sun, it always appears in the east before sunrise.

Because – as Earth orbits the sun – all the stars rise two hours earlier with each passing month, Orion is now higher at dawn than a month ago.

As seen from the Northern Hemisphere, Orion precedes Sirius the Dog Star into the sky. After Orion first appears at morning dawn, you can count on Sirius to appear in the morning sky a few weeks later. You should be able to see Sirius at or before dawn right now – unless you live at far northern latitudes.

But, even from Earth’s far north, you won’t have much longer to wait to see Sirius!

Be sure to notice the colors of Rigel and Betelgeuse in Orion, and of Sirius itself. When seen low in the sky on a summer morning, you might notice bright Sirius flashing in many colors! In fact – although Rigel and Betelgeuse are intrinsically colorful, due to the types of stars they are – Sirius shines mostly white. The colors we see in Sirius when it’s low in the sky are the result of looking at this very bright star through a greater-than-usual thickness of Earth’s atmosphere in the direction toward the horizons. Image via Amanda Cross. Read more about this image.

Bottom line: A sign of the changing season, Sirius – the sky’s brightest star – is visible before sunup. You’ll know it’s Sirius if the very noticeable three stars in Orion’s Belt point to it.

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In late August and early September, look for a hint of the changing season in the predawn sky: Orion the Hunter and Sirius the Dog Star. The very noticeable constellation Orion the Hunter rises before dawn at this time of year, recognizable for the short straight line of three stars that make up Orion’s Belt. And the sky’s brightest star Sirius – sometimes called the Dog Star because it’s part of the constellation Canis Major the Greater Dog – follows Orion into the sky as the predawn darkness gives way to dawn.

Have you noticed a very bright, madly twinkling star in early morning sky? Many do – around the world – at this time of year. That star is Sirius. It’s so bright that, when it’s low in the sky, it shines with glints of red and flashes of blue – very noticeable!

Orion and the nearby star Sirius will become visible in the evening by northern winter (or southern summer). But presently the Hunter and the Dog Star lord over the sky at dawn’s first light.

EarthSky astronomy kits are perfect for beginners. Order yours from the EarthSky store.

Matthew Chin in Hong Kong caught this photo of the stars and constellations that we in the Northern Hemisphere associate with winter – in late July, 2014. In late August – a full month later – all of these stars will have shifted higher in the east before sunrise. By December, they’ll be ascending in the east in the evening!

Orion was low in the west after sunset around March and April. By June of each year, this constellation lies behind the sun as seen from Earth. Orion only returned to visibility in Earth’s sky about a month ago (see image above). When a constellation becomes visible again, after being behind the sun, it always appears in the east before sunrise.

Because – as Earth orbits the sun – all the stars rise two hours earlier with each passing month, Orion is now higher at dawn than a month ago.

As seen from the Northern Hemisphere, Orion precedes Sirius the Dog Star into the sky. After Orion first appears at morning dawn, you can count on Sirius to appear in the morning sky a few weeks later. You should be able to see Sirius at or before dawn right now – unless you live at far northern latitudes.

But, even from Earth’s far north, you won’t have much longer to wait to see Sirius!

Be sure to notice the colors of Rigel and Betelgeuse in Orion, and of Sirius itself. When seen low in the sky on a summer morning, you might notice bright Sirius flashing in many colors! In fact – although Rigel and Betelgeuse are intrinsically colorful, due to the types of stars they are – Sirius shines mostly white. The colors we see in Sirius when it’s low in the sky are the result of looking at this very bright star through a greater-than-usual thickness of Earth’s atmosphere in the direction toward the horizons. Image via Amanda Cross. Read more about this image.

Bottom line: A sign of the changing season, Sirius – the sky’s brightest star – is visible before sunup. You’ll know it’s Sirius if the very noticeable three stars in Orion’s Belt point to it.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Help support EarthSky! Check out the EarthSky store for fun astronomy gifts and tools for all ages!

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IPCC's land report showed we're entering an era of damage control

The IPCC has published a new report on climate and land. The report includes chapters on land-climate interactions (land use changes are accelerating global warming, which is causing more extreme weather), desertification (deserts are expanding), land degradation (declining quality of soil, for example), and food security. The latter is a particularly critical topic, given our dependence on food and water supplies for survival.

The report notes that humans struggle to efficiently manage our food supply. Between 25 and 30 percent of the food we produce worldwide is wasted. This waste happens for different reasons in different regions – in developed countries, consumers throw out excess food, while in developing countries much of the waste is due to a lack of refrigeration as products go bad between producers and consumers. And of course refrigeration requires energy, meaning that mitigating the latter problem will generate more greenhouse gas emissions. The report estimates that food waste costs about $1 trillion per year and accounts for about 10 percent of greenhouse gas emissions from food systems. Meanwhile, 2 billion humans are overweight or obese while nearly 1 billion are undernourished, highlighting the inefficiencies and inequities in our food distribution.

Overall, 23 percent of human greenhouse gas emissions come from agriculture, forestry, and other land use. Much of this is due to emissions of the more potent greenhouse gases methane (from cattle and rice farming, for example) and nitrous oxide (from nitrogen-fertilized agricultural soils). The figure is comparable to the transportation sector (approximately 15 percent of total human greenhouse gas emissions) and electricity and heat (approximately 30 percent). The report notes that diets heavier in meat and particularly beef adversely impact both greenhouse gas emissions and health outcomes.

Potential to reduce greenhouse gas emissions from changing diets by 2050, per the research cited in the IPCC report.

Continued global warming and the associated intensification of extreme weather are expected to decrease yields in many crops. While farmers can adapt in some ways – using more land, changing the crops they grow, and raising prices – those higher costs will be passed on to consumers. The IPCC report notes that climate change and the socioeconomic path we follow will combine to determine how much food insecurity humanity faces in the coming decades.

As food prices rise, if the number of people in poverty is also increasing, that combination could create widespread hunger crises. The IPCC report envisions various different ‘Shared Socioeconomic Pathways’ in which factors like global population, poverty, inequality, food waste, and diets vary. In a world with a large population, high inequality and poverty, inefficient food use and diets, the risk of food insecurity becomes high at 1.5°C (2.7°F) and very high at 2.5°C (4.5°F). If we follow a more sustainable socioeconomic scenario with a stable global population, low inequality and poverty, efficient food use and diets, the risk of food insecurity becomes high closer to 3°C (5.4°F). Water scarcity is a similar story, with high risks at 1.5°C if we follow a less sustainable socioeconomic pathway, and closer to 3°C if population growth and income inequality are minimized.

The importance of these factors in avoiding widespread crises among poorer populations is among the reasons why modern climate policy proposals like the Green New Deal are aimed at alleviating both inequality and climate change. Adding to the challenge, the nutritional content of many crops, including wheat and rice, will decline in a world with more heat and carbon dioxide. Higher temperatures will also make fruits and vegetables rot more quickly, thus exacerbating the problem of food waste and energy needed for refrigeration.

In short, preventing food and water scarcity in a world with more intense heat and droughts will be a challenge. Slowing global warming by curbing greenhouse gas emissions will help mitigate the problem, but the risks will also depend on the size of the population remaining in poverty. Hence climate policy solutions must address both emissions and socioeconomic inequalities.

The IPCC report lists various adaptation and mitigation measures that could be implemented, including more sustainable food production and diets (more plant-based, less meat-based), improved forest management (including reducing deforestation and increasing reforestation), agricultural carbon sequestration (including no-till farming practices), and reducing food waste. And it warns that delaying action will be costly:

“Deferral of [greenhouse gas] emissions reductions from all sectors implies trade-offs including irreversible loss in land ecosystem functions and services required for food, health, habitable settlements and production, leading to increasingly significant economic impacts on many countries in many regions of the world. Delaying action as is assumed in high emissions scenarios could result in some irreversible impacts on some ecosystems, which in the longer-term has the potential to lead to substantial additional [greenhouse gas] emissions from ecosystems that would accelerate global warming.”

Last year’s IPCC Special Report on climate impacts at 1.5°C concluded that to limit global warming to this level, global greenhouse gas emissions need to decline by about 45 percent below 2010 levels by 2030, which led to many headlines and declarations that we only have 12 years left to avert a climate catastrophe. Reality is more complicated than this simple message; for example, how one defines “catastrophe” is subjective. The IPCC land report documents that the risks associated with food and water insecurity, extreme weather, desertification, land degradation, human conflict, and other climate change threats will only grow as temperatures rise above today’s level of 1°C hotter than pre-industrial temperatures.

However, the report also illustrates that in combination with sustainable and equitable growth, we can always reduce those threats beyond what they would be at higher global temperatures. We are essentially entering an era of permanent damage control. That may not make for as sexy a headline as ’12 years to avert catastrophe,’ but it more accurately describes our state of affairs.

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The IPCC has published a new report on climate and land. The report includes chapters on land-climate interactions (land use changes are accelerating global warming, which is causing more extreme weather), desertification (deserts are expanding), land degradation (declining quality of soil, for example), and food security. The latter is a particularly critical topic, given our dependence on food and water supplies for survival.

The report notes that humans struggle to efficiently manage our food supply. Between 25 and 30 percent of the food we produce worldwide is wasted. This waste happens for different reasons in different regions – in developed countries, consumers throw out excess food, while in developing countries much of the waste is due to a lack of refrigeration as products go bad between producers and consumers. And of course refrigeration requires energy, meaning that mitigating the latter problem will generate more greenhouse gas emissions. The report estimates that food waste costs about $1 trillion per year and accounts for about 10 percent of greenhouse gas emissions from food systems. Meanwhile, 2 billion humans are overweight or obese while nearly 1 billion are undernourished, highlighting the inefficiencies and inequities in our food distribution.

Overall, 23 percent of human greenhouse gas emissions come from agriculture, forestry, and other land use. Much of this is due to emissions of the more potent greenhouse gases methane (from cattle and rice farming, for example) and nitrous oxide (from nitrogen-fertilized agricultural soils). The figure is comparable to the transportation sector (approximately 15 percent of total human greenhouse gas emissions) and electricity and heat (approximately 30 percent). The report notes that diets heavier in meat and particularly beef adversely impact both greenhouse gas emissions and health outcomes.

Potential to reduce greenhouse gas emissions from changing diets by 2050, per the research cited in the IPCC report.

Continued global warming and the associated intensification of extreme weather are expected to decrease yields in many crops. While farmers can adapt in some ways – using more land, changing the crops they grow, and raising prices – those higher costs will be passed on to consumers. The IPCC report notes that climate change and the socioeconomic path we follow will combine to determine how much food insecurity humanity faces in the coming decades.

As food prices rise, if the number of people in poverty is also increasing, that combination could create widespread hunger crises. The IPCC report envisions various different ‘Shared Socioeconomic Pathways’ in which factors like global population, poverty, inequality, food waste, and diets vary. In a world with a large population, high inequality and poverty, inefficient food use and diets, the risk of food insecurity becomes high at 1.5°C (2.7°F) and very high at 2.5°C (4.5°F). If we follow a more sustainable socioeconomic scenario with a stable global population, low inequality and poverty, efficient food use and diets, the risk of food insecurity becomes high closer to 3°C (5.4°F). Water scarcity is a similar story, with high risks at 1.5°C if we follow a less sustainable socioeconomic pathway, and closer to 3°C if population growth and income inequality are minimized.

The importance of these factors in avoiding widespread crises among poorer populations is among the reasons why modern climate policy proposals like the Green New Deal are aimed at alleviating both inequality and climate change. Adding to the challenge, the nutritional content of many crops, including wheat and rice, will decline in a world with more heat and carbon dioxide. Higher temperatures will also make fruits and vegetables rot more quickly, thus exacerbating the problem of food waste and energy needed for refrigeration.

In short, preventing food and water scarcity in a world with more intense heat and droughts will be a challenge. Slowing global warming by curbing greenhouse gas emissions will help mitigate the problem, but the risks will also depend on the size of the population remaining in poverty. Hence climate policy solutions must address both emissions and socioeconomic inequalities.

The IPCC report lists various adaptation and mitigation measures that could be implemented, including more sustainable food production and diets (more plant-based, less meat-based), improved forest management (including reducing deforestation and increasing reforestation), agricultural carbon sequestration (including no-till farming practices), and reducing food waste. And it warns that delaying action will be costly:

“Deferral of [greenhouse gas] emissions reductions from all sectors implies trade-offs including irreversible loss in land ecosystem functions and services required for food, health, habitable settlements and production, leading to increasingly significant economic impacts on many countries in many regions of the world. Delaying action as is assumed in high emissions scenarios could result in some irreversible impacts on some ecosystems, which in the longer-term has the potential to lead to substantial additional [greenhouse gas] emissions from ecosystems that would accelerate global warming.”

Last year’s IPCC Special Report on climate impacts at 1.5°C concluded that to limit global warming to this level, global greenhouse gas emissions need to decline by about 45 percent below 2010 levels by 2030, which led to many headlines and declarations that we only have 12 years left to avert a climate catastrophe. Reality is more complicated than this simple message; for example, how one defines “catastrophe” is subjective. The IPCC land report documents that the risks associated with food and water insecurity, extreme weather, desertification, land degradation, human conflict, and other climate change threats will only grow as temperatures rise above today’s level of 1°C hotter than pre-industrial temperatures.

However, the report also illustrates that in combination with sustainable and equitable growth, we can always reduce those threats beyond what they would be at higher global temperatures. We are essentially entering an era of permanent damage control. That may not make for as sexy a headline as ’12 years to avert catastrophe,’ but it more accurately describes our state of affairs.

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Russian Soyuz docks with ISS on 2nd attempt

The Soyuz MS-14 spacecraft is pictured during its approach. The Soyuz MS-13 is seen in the foreground. Via NASA.

Roscosmos – the Russian space agency – launched its Soyuz MS-14 spacecraft on August 22, 2019, to the International Space Station (ISS). The mission was initially scheduled to dock at the station’s space-facing Poisk module on August 24, 2019. However, the spacecraft was commanded to back away when a malfunction of equipment on the ISS prevented it from locking on to the module. A successful second docking attempt was executed on August 26, 2019, and has now been successful. The Soyuz carries 1,450 pounds of cargo containing food and medical supplies, equipment to aid scientific experiments. Plus it carries Skybot F-850 – a humanoid robot – that will be tested for its functional capabilities in microgravity. The ISS took to Twitter to confirm Soyuz MS-14’s arrival:

The Soyuz MS-14 is home at the Zvezda module! Contact and capture confirmed at 11:08 pm ET. https://t.co/cBNqC5JGaz pic.twitter.com/vc04xod0sm

— Intl. Space Station (@Space_Station) August 27, 2019

The spacecraft with its robot cargo is currently at the station’s Zvezda module; Zvezda is Russian for star.

Watch Skybot being trained to imitate humans.

Follow Skybot on Twitter (in Russian).

Skybot is seen sitting in the commander’s seat of the Soyuz MS-14 spacecraft. It also holds Russia’s flag in its hand. Image via Roscosmos.

Soyuz MS-14’s successful launch

The unmanned spacecraft lifted off without any hitches onboard the Soyuz 2.1a rocket booster from the Baikonur Cosmodrome in Kazakhstan. In addition to testing the humanoid robot Skybot, the mission also aims to assess the spacecraft’s new motion control and navigation systems. The spacecraft’s compatibility with the 2.1a rocket will also be studied since Roscosmos aims to use the rocket to launch Russian crew beginning in spring 2020.

Watch the replay of Soyuz MS-14’s launch over here

The Soyuz MS-14 spacecraft launches from the Baikonur Cosmodrome in Kazakhstan. Image via NASA.

Two smooth days into its journey, it was only when the spacecraft was within about 300 feet (100 meters) of its original target – the ISS’ Poisk module – on August 24 that the fault in the station’s telemetry was realized. To ensure the safety to the crew aboard the ISS, the docking of Soyuz MS-14 was called off and moved a safe distance away.

The unpiloted Soyuz MS-14 spacecraft has safely backed away from the space station after its approach was aborted at 1:36am ET. https://t.co/2igm0cn1Dr pic.twitter.com/FRWusLQNhk

— Intl. Space Station (@Space_Station) August 24, 2019

In order to attempt docking a second time, the Russian cosmonauts manually detached the Soyuz MS-13 from the Zvezda module on August 26, 2019. This 25-minute long Soyuz MS-13’s relocation from the Zvezda module to the Poisk module opened up the former for Soyuz MS-14, where it is currently latched on.

Bottom line: Russia’s Soyuz MS-14 spacecraft has docked safely at the station’s Zvezda module. It carries supplies for the crew and a humanoid robot.

Via Roscosmos

Via NASA

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The Soyuz MS-14 spacecraft is pictured during its approach. The Soyuz MS-13 is seen in the foreground. Via NASA.

Roscosmos – the Russian space agency – launched its Soyuz MS-14 spacecraft on August 22, 2019, to the International Space Station (ISS). The mission was initially scheduled to dock at the station’s space-facing Poisk module on August 24, 2019. However, the spacecraft was commanded to back away when a malfunction of equipment on the ISS prevented it from locking on to the module. A successful second docking attempt was executed on August 26, 2019, and has now been successful. The Soyuz carries 1,450 pounds of cargo containing food and medical supplies, equipment to aid scientific experiments. Plus it carries Skybot F-850 – a humanoid robot – that will be tested for its functional capabilities in microgravity. The ISS took to Twitter to confirm Soyuz MS-14’s arrival:

The Soyuz MS-14 is home at the Zvezda module! Contact and capture confirmed at 11:08 pm ET. https://t.co/cBNqC5JGaz pic.twitter.com/vc04xod0sm

— Intl. Space Station (@Space_Station) August 27, 2019

The spacecraft with its robot cargo is currently at the station’s Zvezda module; Zvezda is Russian for star.

Watch Skybot being trained to imitate humans.

Follow Skybot on Twitter (in Russian).

Skybot is seen sitting in the commander’s seat of the Soyuz MS-14 spacecraft. It also holds Russia’s flag in its hand. Image via Roscosmos.

Soyuz MS-14’s successful launch

The unmanned spacecraft lifted off without any hitches onboard the Soyuz 2.1a rocket booster from the Baikonur Cosmodrome in Kazakhstan. In addition to testing the humanoid robot Skybot, the mission also aims to assess the spacecraft’s new motion control and navigation systems. The spacecraft’s compatibility with the 2.1a rocket will also be studied since Roscosmos aims to use the rocket to launch Russian crew beginning in spring 2020.

Watch the replay of Soyuz MS-14’s launch over here

The Soyuz MS-14 spacecraft launches from the Baikonur Cosmodrome in Kazakhstan. Image via NASA.

Two smooth days into its journey, it was only when the spacecraft was within about 300 feet (100 meters) of its original target – the ISS’ Poisk module – on August 24 that the fault in the station’s telemetry was realized. To ensure the safety to the crew aboard the ISS, the docking of Soyuz MS-14 was called off and moved a safe distance away.

The unpiloted Soyuz MS-14 spacecraft has safely backed away from the space station after its approach was aborted at 1:36am ET. https://t.co/2igm0cn1Dr pic.twitter.com/FRWusLQNhk

— Intl. Space Station (@Space_Station) August 24, 2019

In order to attempt docking a second time, the Russian cosmonauts manually detached the Soyuz MS-13 from the Zvezda module on August 26, 2019. This 25-minute long Soyuz MS-13’s relocation from the Zvezda module to the Poisk module opened up the former for Soyuz MS-14, where it is currently latched on.

Bottom line: Russia’s Soyuz MS-14 spacecraft has docked safely at the station’s Zvezda module. It carries supplies for the crew and a humanoid robot.

Via Roscosmos

Via NASA

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Why the Amazon is burning: 4 reasons

A fire in the Amazon rainforest near Humaita, in Amazonas state, Brazil, August 17, 2019. Image via Reuters/Ueslei Marcelino/The Conversation.

By Catesby Holmes, The Conversation

Nearly 40,000 fires are incinerating Brazil’s Amazon rainforest, the latest outbreak in an overactive fire season that has charred 1,330 square miles (2,927 square km) of the rainforest this year.

Don’t blame dry weather for the swift destruction of the world’s largest tropical forest, say environmentalists. These Amazonian wildfires are a human-made disaster, set by loggers and cattle ranchers who use a “slash and burn” method to clear land. Feeding off very dry conditions, some of those fires have spread out of control.

Brazil has long struggled to preserve the Amazon, sometimes called the “lungs of the world” because it produces 20% of the world’s oxygen. Despite the increasingly strict environmental protections of recent decades, about a quarter of this massive rainforest is already gone – an area the size of Texas.

While climate change endangers the Amazon, bringing hotter weather and longer droughts, development may be the greatest threat facing the rainforest.

Here, environmental researchers explain how farming, big infrastructure projects and roads drive the deforestation that’s slowly killing the Amazon.

Huge fires are raging across multiple regions of the Amazon Basin. Image via Guaira Maia/ISA/The Conversation.

1. Farming in the jungle

Rachel Garrett is a professor at Boston University who studies land use in Brazil. She said:

Deforestation is largely due to land clearing for agricultural purposes, particularly cattle ranching but also soybean production.

Since farmers need a massive amount of land for grazing, Garrett says, they are driven to

… continuously clear forest – illegally – to expand pastureland.

Twelve percent of what was once Amazonian forest – about 93 million acres – is now farmland.

Cattle farming is one of the main industries in the Amazon region. Image via Nacho Doce/Reuters/The Conversation.

Deforestation in the Amazon has spiked since the election last year of the far-right President Jair Bolsonaro. Arguing that federal conservation zones and hefty fines for cutting down trees hinder economic growth, Bolsonaro has slashed Brazil’s strict environmental regulations.

There’s no evidence to support Bolsonaro’s view, Garrett says. She said:

Food production in the Amazon has substantially increased since 2004.

The increased production has been pushed by federal policies meant to discourage land clearing, such as hefty fines for deforestation and low-interest loans for investing in sustainable agricultural practices. Farmers are now planting and harvesting two crops – mostly soybean and corn – each year, rather than just one.

Brazilian environmental regulations helped Amazonian ranchers, too.

Garrett’s research found that improved pasture management in line with stricter federal land use policies led the number of cattle slaughtered annually per acre to double. She wrote:

Farmers are producing more meat – and therefore earning more money – with their land.

2. Infrastructure development and deforestation

President Bolsonaro is also pushing forward an ambitious infrastructure development plan that would turn the Amazon’s many waterways into electricity generators.

The Brazilian government has long wanted to build a series of big new hydroelectric dams, including on the Tapajós River, the Amazon’s only remaining undammed river. But the indigenous Munduruku people, who live near around the Tapajós River, have stridently opposed this idea.

According to Robert T. Walker, a University of Florida professor who has conducted environmental research in the Amazon for 25 years:

The Munduruku have until now successfully slowed down and seemingly halted many efforts to profit off the Tapajós.

But Bolsonaro’s government is less likely than his predecessors to respect indigenous rights. One of his first moves in office was to transfer responsibilities for demarcating indigenous lands from the Brazilian Ministry of Justice to the decidedly pro-development Ministry of Agriculture.

And, Walker notes, Bolsonaro’s Amazon development plans are part of a broader South American project, conceived in 2000, to build continental infrastructure that provides electricity for industrialization and facilitates trade across the region.

For the Brazilian Amazon, that means not just new dams but also “webs of waterways, rail lines, ports and roads” that will get products like soybeans, corn and beef to market, according to Walker. He said:

This plan is far more ambitious than earlier infrastructure projects that damaged the Amazon.

If Bolsonaro’s plan moves forward, he estimates that fully 40% of the Amazon could be deforested.

3. Road-choked streams

Roads, most of them dirt, already criss-cross the Amazon.

That came as a surprise to Cecilia Gontijo Leal, a Brazilian researcher who studies tropical fish habitats. She wrote:

I imagined that my field work would be all boat rides on immense rivers and long jungle hikes. In fact, all my research team needed was a car.

Perched culverts disrupt the water flow of Amazonian streams, isolating fish. Image via the author.

Traveling on rutted mud roads to take water samples from streams across Brazil’s Pará state, Leal realized that the informal “bridges” of this locally built transportation network must be impacting Amazonian waterways. So she decided to study that, too. She said:

We found that makeshift road crossings cause both shore erosion and silt buildup in streams. This worsens water quality, hurting the fish that thrive in this delicately balanced habitat.

The ill-designed road crossings – which feature perched culverts that disrupt water flow – also act as barriers to movement, preventing fish from finding places to feed, breed and take shelter.

4. Rewilding tropical forests

The fires now consuming vast swaths of the Amazon are the latest repercussion of development in the Amazon.

Set by farmers likely emboldened by their president’s anti-conservation stance, the blazes emit so much smoke that on August 20 it blotted out the midday sun in the city of São Paulo, 1,700 miles (2,736 km) away. The fires are still multiplying, and peak dry season is still a month away.

Apocalyptic as this sounds, science suggests it’s not too late to save the Amazon.

Tropical forests destroyed by fire, logging, land-clearing and roads can be replanted, say ecologists Robin Chazdon and Pedro Brancalion.

Using satellite imagery and the latest peer-reviewed research on biodiversity, climate change and water security, Chazdon and Brancalion identified 385,000 square miles (997,145 square km) of “restoration hotspots” – areas where restoring tropical forests would be most beneficial, least costly and lowest risk. Chazon wrote:

Although these second-growth forests will never perfectly replace the older forests that have been lost, planting carefully selected trees and assisting natural recovery processes can restore many of their former properties and functions.

The five countries with the most tropical restoration potential are Brazil, Indonesia, India, Madagascar and Colombia.

Editor’s note: This story is a roundup of articles from The Conversation’s archives.

Catesby Holmes, Global Affairs Editor, The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Causes of wildfires burning Brazil’s Amazon rainforest in August 2019.

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A fire in the Amazon rainforest near Humaita, in Amazonas state, Brazil, August 17, 2019. Image via Reuters/Ueslei Marcelino/The Conversation.

By Catesby Holmes, The Conversation

Nearly 40,000 fires are incinerating Brazil’s Amazon rainforest, the latest outbreak in an overactive fire season that has charred 1,330 square miles (2,927 square km) of the rainforest this year.

Don’t blame dry weather for the swift destruction of the world’s largest tropical forest, say environmentalists. These Amazonian wildfires are a human-made disaster, set by loggers and cattle ranchers who use a “slash and burn” method to clear land. Feeding off very dry conditions, some of those fires have spread out of control.

Brazil has long struggled to preserve the Amazon, sometimes called the “lungs of the world” because it produces 20% of the world’s oxygen. Despite the increasingly strict environmental protections of recent decades, about a quarter of this massive rainforest is already gone – an area the size of Texas.

While climate change endangers the Amazon, bringing hotter weather and longer droughts, development may be the greatest threat facing the rainforest.

Here, environmental researchers explain how farming, big infrastructure projects and roads drive the deforestation that’s slowly killing the Amazon.

Huge fires are raging across multiple regions of the Amazon Basin. Image via Guaira Maia/ISA/The Conversation.

1. Farming in the jungle

Rachel Garrett is a professor at Boston University who studies land use in Brazil. She said:

Deforestation is largely due to land clearing for agricultural purposes, particularly cattle ranching but also soybean production.

Since farmers need a massive amount of land for grazing, Garrett says, they are driven to

… continuously clear forest – illegally – to expand pastureland.

Twelve percent of what was once Amazonian forest – about 93 million acres – is now farmland.

Cattle farming is one of the main industries in the Amazon region. Image via Nacho Doce/Reuters/The Conversation.

Deforestation in the Amazon has spiked since the election last year of the far-right President Jair Bolsonaro. Arguing that federal conservation zones and hefty fines for cutting down trees hinder economic growth, Bolsonaro has slashed Brazil’s strict environmental regulations.

There’s no evidence to support Bolsonaro’s view, Garrett says. She said:

Food production in the Amazon has substantially increased since 2004.

The increased production has been pushed by federal policies meant to discourage land clearing, such as hefty fines for deforestation and low-interest loans for investing in sustainable agricultural practices. Farmers are now planting and harvesting two crops – mostly soybean and corn – each year, rather than just one.

Brazilian environmental regulations helped Amazonian ranchers, too.

Garrett’s research found that improved pasture management in line with stricter federal land use policies led the number of cattle slaughtered annually per acre to double. She wrote:

Farmers are producing more meat – and therefore earning more money – with their land.

2. Infrastructure development and deforestation

President Bolsonaro is also pushing forward an ambitious infrastructure development plan that would turn the Amazon’s many waterways into electricity generators.

The Brazilian government has long wanted to build a series of big new hydroelectric dams, including on the Tapajós River, the Amazon’s only remaining undammed river. But the indigenous Munduruku people, who live near around the Tapajós River, have stridently opposed this idea.

According to Robert T. Walker, a University of Florida professor who has conducted environmental research in the Amazon for 25 years:

The Munduruku have until now successfully slowed down and seemingly halted many efforts to profit off the Tapajós.

But Bolsonaro’s government is less likely than his predecessors to respect indigenous rights. One of his first moves in office was to transfer responsibilities for demarcating indigenous lands from the Brazilian Ministry of Justice to the decidedly pro-development Ministry of Agriculture.

And, Walker notes, Bolsonaro’s Amazon development plans are part of a broader South American project, conceived in 2000, to build continental infrastructure that provides electricity for industrialization and facilitates trade across the region.

For the Brazilian Amazon, that means not just new dams but also “webs of waterways, rail lines, ports and roads” that will get products like soybeans, corn and beef to market, according to Walker. He said:

This plan is far more ambitious than earlier infrastructure projects that damaged the Amazon.

If Bolsonaro’s plan moves forward, he estimates that fully 40% of the Amazon could be deforested.

3. Road-choked streams

Roads, most of them dirt, already criss-cross the Amazon.

That came as a surprise to Cecilia Gontijo Leal, a Brazilian researcher who studies tropical fish habitats. She wrote:

I imagined that my field work would be all boat rides on immense rivers and long jungle hikes. In fact, all my research team needed was a car.

Perched culverts disrupt the water flow of Amazonian streams, isolating fish. Image via the author.

Traveling on rutted mud roads to take water samples from streams across Brazil’s Pará state, Leal realized that the informal “bridges” of this locally built transportation network must be impacting Amazonian waterways. So she decided to study that, too. She said:

We found that makeshift road crossings cause both shore erosion and silt buildup in streams. This worsens water quality, hurting the fish that thrive in this delicately balanced habitat.

The ill-designed road crossings – which feature perched culverts that disrupt water flow – also act as barriers to movement, preventing fish from finding places to feed, breed and take shelter.

4. Rewilding tropical forests

The fires now consuming vast swaths of the Amazon are the latest repercussion of development in the Amazon.

Set by farmers likely emboldened by their president’s anti-conservation stance, the blazes emit so much smoke that on August 20 it blotted out the midday sun in the city of São Paulo, 1,700 miles (2,736 km) away. The fires are still multiplying, and peak dry season is still a month away.

Apocalyptic as this sounds, science suggests it’s not too late to save the Amazon.

Tropical forests destroyed by fire, logging, land-clearing and roads can be replanted, say ecologists Robin Chazdon and Pedro Brancalion.

Using satellite imagery and the latest peer-reviewed research on biodiversity, climate change and water security, Chazdon and Brancalion identified 385,000 square miles (997,145 square km) of “restoration hotspots” – areas where restoring tropical forests would be most beneficial, least costly and lowest risk. Chazon wrote:

Although these second-growth forests will never perfectly replace the older forests that have been lost, planting carefully selected trees and assisting natural recovery processes can restore many of their former properties and functions.

The five countries with the most tropical restoration potential are Brazil, Indonesia, India, Madagascar and Colombia.

Editor’s note: This story is a roundup of articles from The Conversation’s archives.

Catesby Holmes, Global Affairs Editor, The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Causes of wildfires burning Brazil’s Amazon rainforest in August 2019.

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Cranes heading south

Image via Jörgen Andersson.

from EarthSky https://ift.tt/2KZXY1D

Image via Jörgen Andersson.

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Before dawn, Orion the Hunter

Mike wrote:

I noticed on your site that Orion returned to the predawn sky in late July. You called it the ‘ghost of the summer dawn.’ Due to cloudy skies and other conditions, I was not able to see it until August 6. When will Orion return to the evening sky?

Mike, Orion the Hunter – one of most noticeable constellations, with a short, straight row of three medium-bright stars at its mid-section – is always behind the sun as seen from Earth in June. It comes back to the predawn sky every year in late July or early August. By late August and early September, Orion is rising in the wee hours and is well up in the dawn sky, an hour before dawn, as shown on today’s chart.

Orion will soon be up by midnight, then 10 p.m. … and by December you’ll find it rising in early evening.

There’s nothing unusual about Orion’s shift from the predawn to the evening sky. This constellation is simply following the westward shift of all the stars, caused by Earth’s orbit around the sun. As we orbit the sun, our night sky points toward an ever-changing panorama of the Milky Way galaxy. Our orbit causes all the stars to rise approximately 4 minutes earlier each day.

Martin Marthadinata in East Java, Indonesia, caught this photo on September 11, 2016. It’s Orion rising behind the rooftops. Notice Orion’s Belt of 3 stars.

Bottom line: If you’re an early riser, look to the southeast and spot Orion the Hunter roaming the September predawn sky.

Help support EarthSky! Visit the EarthSky store for to see the great selection of educational tools and team gear we have to offer.

from EarthSky https://ift.tt/2U5WeXu

Mike wrote:

I noticed on your site that Orion returned to the predawn sky in late July. You called it the ‘ghost of the summer dawn.’ Due to cloudy skies and other conditions, I was not able to see it until August 6. When will Orion return to the evening sky?

Mike, Orion the Hunter – one of most noticeable constellations, with a short, straight row of three medium-bright stars at its mid-section – is always behind the sun as seen from Earth in June. It comes back to the predawn sky every year in late July or early August. By late August and early September, Orion is rising in the wee hours and is well up in the dawn sky, an hour before dawn, as shown on today’s chart.

Orion will soon be up by midnight, then 10 p.m. … and by December you’ll find it rising in early evening.

There’s nothing unusual about Orion’s shift from the predawn to the evening sky. This constellation is simply following the westward shift of all the stars, caused by Earth’s orbit around the sun. As we orbit the sun, our night sky points toward an ever-changing panorama of the Milky Way galaxy. Our orbit causes all the stars to rise approximately 4 minutes earlier each day.

Martin Marthadinata in East Java, Indonesia, caught this photo on September 11, 2016. It’s Orion rising behind the rooftops. Notice Orion’s Belt of 3 stars.

Bottom line: If you’re an early riser, look to the southeast and spot Orion the Hunter roaming the September predawn sky.

Help support EarthSky! Visit the EarthSky store for to see the great selection of educational tools and team gear we have to offer.

from EarthSky https://ift.tt/2U5WeXu

Skeptical Science New Research for Week #34, 2019

 44 items this week, with 9 available as open access.

Articles:

Humans dealing with global warming

Future Heat Stress During Muslim Pilgrimage (Hajj) Projected to Exceed “Extreme Danger” Levels

Impact of Water Level Rise on Urban Infrastructures: Washington, DC, and Shanghai as Case Studies

Not all carbon dioxide emission scenarios are equally likely: a subjective expert assessment

Decarbonization and its discontents: a critical energy justice perspective on four low-carbon transitions (open access)

Pitfalls in comparing Paris pledges (open access)

Real options analysis of climate-change adaptation: investment flexibility and extreme weather events

A strategy to assess the uncertainty of a climate change impact on extreme hydrological events in the semi-arid Dehbar catchment in Iran

Tracking the progress of climate change adaptation: An Australian case study

Meeting GHG reduction targets requires accounting for all forest sector emissions (open access)

Comparative study on institutional designs and performance of national greenhouse gas inventories: the cases of Vietnam and the Philippines

Transformative adaptation to climate change for sustainable social-ecological systems

Transitioning towards negative CO₂ emissions

Biology and global warming

Responses of the northern Bering Sea and southeastern Bering Sea pelagic ecosystems following record‐breaking low winter sea‐ice

Climate change increases potential plant species richness on Puerto Rican uplands

Extreme warming rates affecting alpine areas in SW Europe deduced from algal lipids (open access)

Maize yield under a changing climate: The hidden role of vapor pressure deficit

Detecting temporal changes in the temperature sensitivity of spring phenology with global warming: Application of machine learning in phenological model

Evaluating impacts of climate change on net ecosystem productivity (NEP) of global different forest types based on an individual tree-based model FORCCHN and remote sensing

Extensive Land Cover Change Across Arctic‐Boreal Northwestern North America from Disturbance and Climate Forcing

Surprising lack of sensitivity of biochemical limitation of photosynthesis of nine tree species to open‐air experimental warming and reduced rainfall in a southern boreal forest

Fish communities diverge in species but converge in traits over three decades of warming

Contrasting consequences of climate change for migratory geese: Predation, density dependence and carryover effects offset benefits of high‐arctic warming

Spatial heterogeneity in climate change effects decouples the long‐term dynamics of wild reindeer populations in the high Arctic

Climate change erodes competitive hierarchies among native, alien and range-extending crabs

Agriculture and global warming

Global warming impact on confined livestock in buildings: efficacy of adaptation measures to reduce heat stress for growing-fattening pigs (open access)

Variable effects of 2°C air warming on yield formation under elevated [CO₂] in a Chinese double rice cropping system

Assessment of global drought propensity and its impacts on agricultural water use in future climate scenarios

Physical science of global warming

Carbon chemistry of intact versus chronically drained peatlands in the southeastern USA

Attributing Greenland warming patterns to regional Arctic sea ice loss

Quantification of Surface Forcing Requirements for a Greenland Ice Sheet Model Using Uncertainty Analyses

Real options analysis of climate-change adaptation: investment flexibility and extreme weather events

CMIP5 model selection for ISMIP6 ice sheet model forcing: Greenland and Antarctica (open access)

Global response of parameterised convective cloud fields to anthropogenic aerosol forcing (open access)

An increasing trend in the ratio of transpiration to total terrestrial evapotranspiration in China from 1982 to 2015 caused by greening and warming

On the Causes and Consequences of Recent Trends in Atmospheric Methane (open access)

Hydrological and temperature variations between 1900 and 2016 in the Catskill Mountains, New York, USA

Temperature variation at the low‐latitude regions of East Asia recorded by tree rings during the past six centuries

Evaluation of the Climate Extremes Index over the United States using 20th and Mid‐21st Century NARCCAP Data

Geology and global warming

Uncertainty in geomorphological responses to climate change (open access)

Suggestions

Please let us know if you're aware of an article you think may be of interest for Skeptical Science research news, or if we've missed something that may be important. Send your input to Skeptical Science via our contact form.

The previous edition of Skeptical Science new research may be found here. 

 

from Skeptical Science https://ift.tt/2zps0FC

 44 items this week, with 9 available as open access.

Articles:

Humans dealing with global warming

Future Heat Stress During Muslim Pilgrimage (Hajj) Projected to Exceed “Extreme Danger” Levels

Impact of Water Level Rise on Urban Infrastructures: Washington, DC, and Shanghai as Case Studies

Not all carbon dioxide emission scenarios are equally likely: a subjective expert assessment

Decarbonization and its discontents: a critical energy justice perspective on four low-carbon transitions (open access)

Pitfalls in comparing Paris pledges (open access)

Real options analysis of climate-change adaptation: investment flexibility and extreme weather events

A strategy to assess the uncertainty of a climate change impact on extreme hydrological events in the semi-arid Dehbar catchment in Iran

Tracking the progress of climate change adaptation: An Australian case study

Meeting GHG reduction targets requires accounting for all forest sector emissions (open access)

Comparative study on institutional designs and performance of national greenhouse gas inventories: the cases of Vietnam and the Philippines

Transformative adaptation to climate change for sustainable social-ecological systems

Transitioning towards negative CO₂ emissions

Biology and global warming

Responses of the northern Bering Sea and southeastern Bering Sea pelagic ecosystems following record‐breaking low winter sea‐ice

Climate change increases potential plant species richness on Puerto Rican uplands

Extreme warming rates affecting alpine areas in SW Europe deduced from algal lipids (open access)

Maize yield under a changing climate: The hidden role of vapor pressure deficit

Detecting temporal changes in the temperature sensitivity of spring phenology with global warming: Application of machine learning in phenological model

Evaluating impacts of climate change on net ecosystem productivity (NEP) of global different forest types based on an individual tree-based model FORCCHN and remote sensing

Extensive Land Cover Change Across Arctic‐Boreal Northwestern North America from Disturbance and Climate Forcing

Surprising lack of sensitivity of biochemical limitation of photosynthesis of nine tree species to open‐air experimental warming and reduced rainfall in a southern boreal forest

Fish communities diverge in species but converge in traits over three decades of warming

Contrasting consequences of climate change for migratory geese: Predation, density dependence and carryover effects offset benefits of high‐arctic warming

Spatial heterogeneity in climate change effects decouples the long‐term dynamics of wild reindeer populations in the high Arctic

Climate change erodes competitive hierarchies among native, alien and range-extending crabs

Agriculture and global warming

Global warming impact on confined livestock in buildings: efficacy of adaptation measures to reduce heat stress for growing-fattening pigs (open access)

Variable effects of 2°C air warming on yield formation under elevated [CO₂] in a Chinese double rice cropping system

Assessment of global drought propensity and its impacts on agricultural water use in future climate scenarios

Physical science of global warming

Carbon chemistry of intact versus chronically drained peatlands in the southeastern USA

Attributing Greenland warming patterns to regional Arctic sea ice loss

Quantification of Surface Forcing Requirements for a Greenland Ice Sheet Model Using Uncertainty Analyses

Real options analysis of climate-change adaptation: investment flexibility and extreme weather events

CMIP5 model selection for ISMIP6 ice sheet model forcing: Greenland and Antarctica (open access)

Global response of parameterised convective cloud fields to anthropogenic aerosol forcing (open access)

An increasing trend in the ratio of transpiration to total terrestrial evapotranspiration in China from 1982 to 2015 caused by greening and warming

On the Causes and Consequences of Recent Trends in Atmospheric Methane (open access)

Hydrological and temperature variations between 1900 and 2016 in the Catskill Mountains, New York, USA

Temperature variation at the low‐latitude regions of East Asia recorded by tree rings during the past six centuries

Evaluation of the Climate Extremes Index over the United States using 20th and Mid‐21st Century NARCCAP Data

Geology and global warming

Uncertainty in geomorphological responses to climate change (open access)

Suggestions

Please let us know if you're aware of an article you think may be of interest for Skeptical Science research news, or if we've missed something that may be important. Send your input to Skeptical Science via our contact form.

The previous edition of Skeptical Science new research may be found here. 

 

from Skeptical Science https://ift.tt/2zps0FC