Showing posts with label rain. Show all posts
Showing posts with label rain. Show all posts

Friday, September 29, 2017

Tropical forests used to protect us from climate change

Tropical forests used to protect us from climate change. Now, scientists say, they’re making it worse

A surprising scientific study released Thursday presents troubling news about the enormous forests of the planet's tropical midsection — suggesting that they are releasing hundreds of millions of tons of carbon to the atmosphere, rather than storing it in the trunks of trees and other vegetation.

The results, published in the journal Science, contradict prior work in suggesting that these forests — including the Amazon rain forest but also huge tropical forests in Indonesia, Congo and elsewhere — have become another net addition to the climate change problem. However, the accounting also implies that if the current losses could be reversed, the forests could also rapidly transform into a powerful climate change solution.

"The losses due to deforestation and degradation are actually emitting more CO2 to the atmosphere, compared with how much the existing forest is able to absorb," said Alessandro Baccini, the lead author of the study and a researcher at the Woods Hole Research Center. He conducted the study with fellow scientists from Woods Hole and Boston University.


(http://www.washingtonpost.com/amphtml/news/energy-environment/wp/2017/09/28/tropical-forests-used-to-protect-us-from-climate-change-a-new-study-says-theyre-now-making-it-worse/

Friday, June 21, 2013

Could big bills from extreme weather drive climate action?

LONDON (Thomson Reuters Foundation) – Could the growing costs of damage from extreme weather – in rich countries as well as poor – be the push that finally drives action on climate change?

House inundated by the Elbe river

Worst-in-a-decade flooding that swept through Germany as U.N. climate talks took place there this month will cost Germany’s government and its insurance companies up to $8 billion, experts estimate. In the United States, the bill for recovery from Hurricane Sandy is estimated at more than $50 billion, with agricultural losses from that country’s widespread drought last year even more costly.

“When you add up what all the extreme weather events cost last year (in the United States), it’s in excess of $250 billion,” said Rachel Kyte, vice president for sustainable development at the World Bank. “You’re talking about economic devastation that at some point is going to start hitting.”

So far, such heavy losses have not led to widespread political support for action on climate change in the United States, or other hard-hit countries. But a new report from the World Bank on the expected impacts of climate shifts suggests that so-called “loss and damage” from extreme weather is just starting, and the costs – in lives, economic damage and even potentially political stability – could rise dramatically around the world.

In South Asia, the once-regular Asian monsoon is growing less predictable, leading to deepening concerns that shifts could affect the food security and lives of 1.6 billion people. This year, the monsoon arrived almost a month early, causing severe flooding in some parts of India. At other times it has come late, leading to widespread power blackouts as desperate farmers switch on irrigation pumps, said Erick Fernandes, an adviser on climate change and natural resources for the World Bank.

Worsening drought in the Amazon threatens rainfall in food-producing areas of South America as far south as Argentina, he said, during a seminar on the World Bank report at the offices of the International Institute for Environment and Development (IIED) in London.

Brazil’s crops – which are widely exported to other countries as well as feeding Brazilians – are 95 percent rainfed, Fernandes said, and the country relies heavily on hydropower for its energy.

Ocean acidification, as the world’s seas absorb excess carbon dioxide in the atmosphere, has risen by 30 percent from pre-industrial times, the seminar heard. Acidification could prevent many shellfish from growing shells while an expected global temperature rises of at least 4 degrees Celsius would kill most coral reefs around the world, threatening tourism income and leaving coasts now protected by reefs more vulnerable to storms.

The Caribbean alone earns $5 billion a year from its coral reefs, Fernandes said.

TWO DEGREES HOTTER

Much of southern and southwest Africa is expected to see worsening drought by 2030 that could make growing maize – the region’s staple – impossible in 40 percent of the area it is now cultivated, the report said. Rising carbon dioxide in the atmosphere is also likely to turn many of Africa’s grass savannahs to brushy woodlands, affecting pastoralists.

In Southeast Asia, where coastal cities are seeing a big population surge, particularly in informal settlements, rising temperatures are expected to make life extremely uncomfortable for those without access to air conditioning, and to drive a serious increase in the severity of storms that could flood homes and workplaces – as happened in Thailand in 2011, said Fernandes.

Such shifts, besides causing huge financial losses, are likely to force a complete revamp of existing development plans.

“The development paradigm we’ve been peddling for years, that it’s easier to deal with the poor in urban settings than rural, because they’re easier to find and reach with services” may now be wrong, Kyte said.

“This report says that perhaps the most dangerous place to be if you’re poor is in the slums of a southeast Asian city.”

Changes are coming faster than expected, Fernandes said, noting that there was now a chance that a 4 degree Celsius rise in temperatures could arrive by 2060, and that “we could experience a 2-degree (hotter) world in our lifetimes”.

The increasingly extreme weather of recent years is the result of a 0.8 degree Celsius rise in the world’s temperature since pre-industrial times, which suggests that “even 2 degrees is not going to be a picnic”, he said.

Saleemul Huq, director of the International Centre for Climate Change and Development in Bangladesh, and a senior fellow at the IIED, said he saw the World Bank report as “all about loss and damage” – a relatively new term that describes the costs associated with failure to reduce or adapt to climate change.

Who might pay those costs remains a huge political question. Rich countries at the U.N. climate talks have so far refused to accept any liability for their higher carbon emissions, fearing it could lead to them having to pay billions in compensation, experts say.

That suggests many countries, companies and communities will be asked to shoulder the rising costs of extreme weather themselves – and those costs could lead to growing pressure for action, experts predicted. More

 

Wednesday, October 10, 2012

Global Warming May Shift Summer Weather Patterns

By altering the heat balance between land and sea, manmade global warming may be altering summer weather patterns in the Northern Hemisphere, a new study found.

The study, published on Sept. 30 in Nature Geoscience, shows that the sprawling high pressure areas that set up shop over the Western North Atlantic and North Pacific Oceans during the summer months have become larger and stronger during the past 40 years, and these trends are likely to continue during the next several decades as temperatures increase.

These changing weather patterns could have far-reaching impacts, from redirecting powerful hurricanes toward the East Coast, to making the Southeast and Central states see-saw more frequently between extremely hot and dry summers and cooler, wetter summers. In addition, a shift in the strength and shape of the North Pacific subtropical high could affect the South Asian Monsoon, which is already being altered by warming and increased regional pollution.

The study does not formally attribute the cause of the recent trends, but says that the future changes will most likely be driven by global warming.

Although highs (the big "H" symbols on your local TV weathercast) are typically associated with pleasant weather, the position and shape of these systems shape large-scale weather patterns, helping to determine the locations of subtropical deserts. More importantly for the U.S., they help steer the most powerful storms on Earth, and modulate rainfall amounts in the Central, Southeast, and Mid-Atlantic states.

The Atlantic subtropical high, more commonly known as the “Bermuda High” because of its semi-permanent location near that Western Atlantic island during the summer months, helps determine whether Atlantic hurricanes recurve harmlessly out to sea before reaching the East Coast, or make landfall with potentially devastating impacts.

Hurricanes tend to skirt around the edges of the high by catching a ride on the clockwise flow of air around the periphery.

The Bermuda High also helps draw warm and humid air up the Eastern seaboard, contributing to some of the most intense heatwaves on record.

The study, which relies on climate model simulations as well as weather data for the past 40 years, shows that the Bermuda High has already expanded westward, which could be making summertime rainfall in the Central and Southeast U.S. much more variable. More