NASA images show fall in China pollution over virus shutdown

PHYS.ORG

Nitrous oxide levels over China.
Jan. 1st, 2020 (l.). Feb. 25th, 2020.
Nasa images.

NASA satellite images show a dramatic fall in pollution over China that is "partly related" to the economic slowdown due to the coronavirus outbreak, the space agency said. Story here.

Climate Change: Life’s a beach - a disappearing one!

natureresearch

A Pexels photo.

Half of the world's beaches, many of which are in densely populated areas, could disappear by the end of the century under current trends of climate change and sea level rise, suggests a paper published in Nature Climate Change. 

Sandy beaches occupy more than one third of the global coastline and have high socio-economic value. Beaches also provide natural coastal protection from marine storms and cyclones. However, erosion, rising sea levels and changing weather patterns threaten the shoreline, its infrastructure and populations.

Michalis Vousdoukas and colleagues analysed a database of satellite images showing shoreline change from 1984 to 2015. The authors extrapolated historical trends to predict future shoreline dynamics under two different climate change scenarios. They determined the ambient shoreline change, driven by physical factors (geological or anthropogenic) and shoreline retreat due to sea level rise. They also examined how erosion from storms may change under climate change and impact shorelines.  

The results of these analyses indicate that around 50% of the world’s sandy beaches are at risk of severe erosion. The risk for erosion is particularly high in certain countries under both climate scenarios, including The Gambia and Guinea-Bissau, where over 60% of sandy coastline may be lost. When the total length of sandy beach projected to be lost is analysed, Australia would be the worst affected with nearly 12,000 km at risk. Canada, Chile, Mexico, China and the United States would also be greatly affected. Additional research could further improve these estimates, which may be impacted by human intervention.

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In the line of fire

Nature Climate Change 

The bushfires burning in Australia have led to widespread local and global calls for increased efforts to mitigate climate change. Details here.

Full impact of mysterious Brazil oil spill remains unknown

BirdLife

International

Last summer, an oil spill of unknown origin hit Brazil’s northeast coast – just as migrating shorebirds arrived in the area. Our Partner SAVE Brasil has been campaigning for action and striving to measure the impact on birds - but more support is urgently needed. More here.

New research shows, human exploitation of fossil fuels may be playing an even bigger role in our climate crisis than earlier thought.

Extraction of Earth's oil, gas and coal reserves is probably unleashing vastly more methane (CH4) into the air than is currently being estimated. Methane is a potent greenhouse gas and significant contributor to the dangerous heating of our planet. 

by Larry Powell.

Pump jacks extract crude oil from the Bakken field southeastern Saskatchewan, Canada. Are such operations releasing even more methane than we once thought? A PinP photo.

Using the largest ice drill in the world (below), the researchers “looked back in time” to the 17 hundreds, by drilling deep into the ice in Greenland and Antarctica.  

The Blue Ice Drill, used to collect 

the cores used in this study. 

Photo by B. Hmiel.

                                                                       By analyzing air bubbles trapped, both in the ice cores and the snow, they were able to measure how much methane was escaping into the air at the time. Since this was the “pre-industrial era,” before major human expansion of fossil fuel development began, those emissions would have virtually all come from natural sources like natural gas seeps from beneath the ocean floor and mud volcanoes (below) and ancient, but mostly undisturbed deposits of fossil fuels.

Mud volcanoes on the Nahlin Plateau, BC, Canada. 
Are such sites not quite the "climate culprits" 
they were once considered? Photo by Hkeyser.

The findings were surprising. Methane originating from those natural sources were shown to be minimal - only about 1.6 teragrams per year, or 5.4 teragrams, at most. (A teragram is equal to one trillion grams.) As the study concludes, that was "an order of magnitude lower than the currently used estimates." Put another way, those estimates are probably some ten times higher than these new test results show.

Ice cores from the 1870s, however, tell a different story. They show significantly higher methane levels. By then, the industrial revolution had begun, with major extraction of fossil fuels well under way. While fossil fuel extraction would have been the main factor in the increase, other human activities such as rice farming and domestic livestock production would likely also have played a part.

So, the lesson learned from all of this? Emissions due to human activity have been underestimated by anywhere from 25% to 40%. In other words, they are much larger than previously suggested.

Regardless of whether it springs from manmade or natural origins, methane is still a potent greenhouse gas (GHG), capable of trapping heat and impacting the climate. And it's up to 36 times more efficient at doing so than is carbon dioxide (C02), the most common GHG. Atmospheric concentrations of methane have more than doubled since the pre-industrial era. 

"The Global Carbon Project" refers to rising methane levels as "an increasingly important component for managing realistic pathways to mitigate climate change. It's an umbrella group of scientific organizations gathering together a common knowledge base in order to "slow down and ultimately stop the increase of GHGs in the atmosphere."

The lead author of this latest research, Dr. Benjamin Hmiel of the University of Rochester tells PinP that, even after methane is combusted, it still has an impact. While it no longer exists as methane, it transforms into carbon dioxide, the most common greenhouse gas.

Dr. Hmiel's international team consisted of 19 scientists from eleven institutions.

The researchers hope their findings will "emphasize the human impact on the atmosphere and climate and will help inform strategies for targeted emissions reductions to mitigate the effects of climate change."

The findings were published in the journal Nature today. 

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These other stories may also interest you.

Millions of abandoned oil wells are leaking methane, climate menace

Satellite data show 'highest emissions ever measured' from U.S. oil and gas operations

Regardless of the decision, Teck Frontier proves the system is still broken

UPDATE:
This company has now withdrawn its application for the mine.

The Pembina Institute

Canada is facing a decision on the biggest oil sands mine proposal in almost a decade. Alberta’s Frontier oil sands mine, proposed by Teck Resources, has gone through a lengthy regulatory process culminating in a recommended approval from a joint federal-provincial review panel and is now under consideration by the federal cabinet. A casual observer might assume that given the potent environmental and economic impacts, this process would have been comprehensive. Yet, the panel's report, which shares the reasoning behind the decision, is remarkably weak on its consideration of climate impacts. More here.

Climate change to create farmland in the north, but at environmental costs, study reveals

PHYS ORG

High Alpine Tundra in Noatak National Preserve, Alaska. 
U.S. Fish & Wildlife Service.

In a warming world, Canada's north may become our breadbasket of the future - but this new "farming frontier" also poses environmental threats from increased carbon emissions to degraded water quality, according to the first-ever study involving University of Guelph researchers.  Story here.