https://www.jpl.nasa.gov/news/news.php?feature=6584Páginas

10/6/14

Carbon pollution Q&A: why Obama's proposal could make climate history

The Guardian. Suzanne Goldenberg, US environment correspondent


Emissions spew out of a large stack at the coal fired Morgantown Generating Station in Newburg, Maryland. Photograph: Mark Wilson/Getty


Why is Obama doing this instead of Congress?

The House voted for cap and trade in 2009, but the bill died in the Senate. Congress has shown no interest in taking up the issue – and half of the Republican members deny climate change is occurring or oppose measures to cut emissions.
Obama said last year he would use his executive authority to deal with climate change, and now he is.

Why is this a big deal in terms of climate change?

Climate legislation would have imposed economy-wide limits on carbon pollution. With that option off the table, this is the next best thing. Power plants are the single biggest source of carbon pollution, responsible for up to 40% of the carbon dioxide emissions that cause climate change. Much of that carbon pollution is produced by burning coal, especially in old plants.
Obama already cut emissions from the second biggest source – transport – with new rules for cars during his first term.

Will they still be able to keep the lights on without coal?

Yes. Cheap natural gas, now available because of fracking, was already squeezing out coal in power plants, and now accounts for about 30% of electricity generation, according to official figures. Hydro, solar, wind, and geothermal power are expanding and make up about 12%. Nuclear accounts for about 19%

Will this mean many more nuclear plants?

Unlikely – because of the multi-billion dollar price tags and long lead time in permitting and construction. Energy experts expect the emissions reductions to come from retrofits, expanding renewable power, and finding ways to reduce waste, such as modernising the electricity grid.

What should I look out for on Monday?

It's still not clear how tough the new regulations will be. Industry and environment groups will be looking at the emissions reductions target but just as much at the starting and finishing lines. Carbon pollution from power plants has been dropping since 2007, because of natural gas and the downturn. A 25% cut on 2005 levels would be much easier to reach than a 25% cut on the – already lower – 2012 levels. People will also be watching to see whether Obama sets even stricter targets farther out in time, for 2030 or 2040.

6/6/14

El Niño 70% likely to arrive in summer, says US weather forecaster

 THE GUARDIAN. 

Complex interaction between atmosphere and warming oceans could unleash fierce weather events 

, US environment correspondent


A satellite thermal map show El Niño conditions developing in the equatorial Pacific Ocean. Shades of red and orange indicate where the water is warmer and above normal sea level. Credits: JPL/Nasa

The chances of an El Niño, the global climate phenomenon that can destroy crops in Asia and offer a relief from harsh winters in North America, were raised to 70% on Thursday. But scientists said the coming El Niño was likely to be of only moderate strength.
In their monthly forecast, scientists from the US government's Climate Prediction Centre said warming sea temperatures in the Pacific continued to create the conditions for an El Niño this summer.
“The chance of El Niño is 70% during the northern hemisphere summer and reaches 80% during the fall and winter,” the centre said. Its ultimate strength had weakened over the last month. “Regardless, the forecasters remain just as confident that El Niño is likely to emerge,” the forecast said.
There has been growing anticipation of an El Niño this year – because of its widespread impacts.
In California, there has been hope that a strong El Niño could be a drought buster. The phenomenon is known for bringing wetter winters to Texas and southern California. They are also good news for Florida and the Caribbean, damping down the hurricane season in the Atlantic.
But El Niños can wreak havoc on fisheries in South America, and worsen droughts in part of Asia, Africa, and Australia.
That type of El Niño, with widespread global impact, has yet to fully materialise, the scientists said. While warmer sea temperatures in the Pacific were building conditions for an El Niño, the scientists said they were still not seeing the inter-action with atmosphere they would expect for a really big event.
“We are slightly favouring a moderate strength El Niño. While we are not ruling it out at this point, we are not expecting to see the next great El Nino,” said Mike Halpert, acting director of the Climate Prediction Centre.
Independent climate scientists said they too were expecting one of only moderate significance.
“We are going to have an E Niño. The question is the strength,” said Kevin Trenberth, a climate scientist at the National Centre for Atmospheric Research. “It hasn't taken off in the last month the way one might have thought if it was going to be a really major event.”
There was still time for a stronger El Niño to develop, however. It typically continues to develop over the summer months.
“We are on the precipice of actually having it here. The ocean has reached the minimum temperature but we are waiting to see the interaction with the atmosphere,” Halpert said. “It is certainly within the realm of possibility that it does become a very strong event but it would take some interaction with the atmosphere that we are not seeing right now.”