Friday, 27 March 2020

Cambodia halts Mekong dams

SCIENCE MAGAZINE - BIODIVERSITY
Edited by Jeffrey Brainard
In a victory for conservation, the Cambodian government announced on 18 March that it is suspending for 10 years plans to build two hydropower dams on the Mekong River. The move helps preserve a freshwater ecosystem that, after the Amazon, is the world’s most biologically diverse. It also supports a vast fishing industry. Cambodia now relies on hydropower for nearly 50% of its electricity, but will turn to coal, natural gas, and solar energy to meet its future power needs. The Mekong begins on the Tibetan Plateau and flows through several countries, including Cambodia and Vietnam, before emptying into the South China Sea. It has been under increasing pressure from development, pollution, and climate change; drought and upstream dams in China have exacerbated recent low water levels in the lower Mekong. Adding to the river system’s woes, Laos opened two hydropower dams on the Mekong’s main branch in the past 6 months, and Cambodia said it may yet build dams on Mekong tributaries. Still, conservationists praised Cambodia’s decision. Maintaining the free flow of the lower Mekong is “the best decision for both people and nature,” Teak Seng, Cambodia country director for the World Wildlife Fund, said in a statement.

Thursday, 5 March 2020

The hand of man shows through once again in a major weather catastrophe.

 by Larry Powell
The Green Wattle Creek bushfire moves 
toward the Southern Highlands township of 
Yanderra, Australia as police evacuate. Dec. 2019.
Photo by Helitak 430.

A new study finds, manmade climate change did, indeed, worsen the bushfires which ravaged much of southeastern Australia late last year and early this year. An international team of seventeen scientists has just concluded, the probability of conditions developing like the ones which kindled the catastrophic blazes “has increased by at least 30% since 1900 as a result of anthropogenic climate change.” 
And that figure could be much higher considering that extreme heat, one of the main factors behind this increase, is underestimated in the models used. The heating of the planet, largely due to human extraction and burning of fossil fuels, has, for some time been shown to be the main factor behind the development of storms that are more intense and frequent than before.

Looking to the future, the study predicts, if the temperature rises 2 ÂșC over 1900 levels, the kind of fire risk which existed during the recent bushfires "will be at least four times more likely." 

Last year was both the hottest and driest in Australia since records began around 1900. Not only were the fires more frequent and intense, they started earlier than usual. They claimed the lives of more than a billion wild animals, thousands of livestock and 34 humans. Almost six thousand buildings were destroyed. And the smoke - which produced air quality hazards some 20 times beyond what were considered levels safe for humans - lingered for months over much of the country.

To quote from the report, "It is well-established that wildfire smoke exposure is associated with respiratory morbidity. Additionally, fine particulate matter in smoke may act as a triggering factor for acute coronary events (such as heart attack-related deaths) as found for previous fires in southeast Australia. Increased bushfire-related risks in a warming climate have significant implications for the health sector."

The research was done by the scientific group, “World Weather Attribution” (WWA). It's a relatively new, international effort to analyze and communicate the possible influences of climate change on extreme weather events.

Monday, 2 March 2020

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.
-30-

Monday, 24 February 2020

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.

Thursday, 20 February 2020

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.

Beyond Covid 19. Are we risking yet another pandemic if we continue to embrace "assembly-line" livestock production into the future?

by Larry Powell No one would argue that Covid 19 demands our undivided attention. Surely,  defeating this "beast" has to be &...