PBMC - Painel Brasileiro de Mudanças Climáticas

Como a mudança climática está deixando os países ricos mais ricos, e os pobres mais pobres

A temperatura está aumentando no mundo como um todo, mas as consequências disso não são as mesmas para todos os países.

No último século, a mudança climática aumentou a desigualdade entre as nações, puxando para baixo o crescimento econômico dos países mais pobres e aumentando a prosperidade de alguns dos países mais ricos do planeta, aponta uma nova pesquisa.

O abismo entre as nações mais pobres e as mais ricas do mundo é 25% maior do que seria sem o aquecimento global entre 1961 e 2010, diz um estudo da Universidade de Stanford, na Califórnia.

Países tropicais africanos foram os mais afetados- os Produtos Internos Brutos da Mauritânia e do Níger estão 40% menores do que estariam se as temperaturas não estivessem aumentando progressivamente.

O Brasil, que é nona maior economia do mundo, teria tido um crescimento 25% maior se não houvesse aquecimento global.

Leia completo em BBC.

Permafrost collapse is accelerating carbon release

The sudden collapse of thawing soils in the Arctic might double the warming from greenhouse gases released from tundra, warn Merritt R. Turetsky and colleagues.


This much is clear: the Arctic is warming fast, and frozen soils are starting to thaw, often for the first time in thousands of years. But how this happens is as murky as the mud that oozes from permafrost when ice melts.

As the temperature of the ground rises above freezing, microorganisms break down organic matter in the soil. Greenhouse gases — including carbon dioxide, methane and nitrous oxide — are released into the atmosphere, accelerating global warming. Soils in the permafrost region hold twice as much carbon as the atmosphere does — almost 1,600 billion tonnes1.

What fraction of that will decompose? Will it be released suddenly, or seep out slowly? We need to find out.

Current models of greenhouse-gas release and climate assume that permafrost thaws gradually from the surface downwards. Deeper layers of organic matter are exposed over decades or even centuries, and some models are beginning to track these slow changes.

But models are ignoring an even more troubling problem. Frozen soil doesn’t just lock up carbon — it physically holds the landscape together. Across the Arctic and Boreal regions, permafrost is collapsing suddenly as pockets of ice within it melt. Instead of a few centimetres of soil thawing each year, several metres of soil can become destabilized within days or weeks. The land can sink and be inundated by swelling lakes and wetlands.

Read More at Nature

Nasa instrument heads to space station to map CO2

Nasa has sent up an instrument to the International Space Station (ISS) to help track carbon dioxide on Earth.

OCO-3, as the observer is called, was launched on a Falcon rocket from Florida in the early hours of Saturday.

The instrument is made from the spare components left over after the assembly of a satellite, OCO-2, which was put in orbit to do the same job in 2014.

The data from two missions should give scientists a clearer idea of how CO2 moves through the atmosphere.

• CO2 emissions reach 'all-time high'
• Nasa mission 'watches Earth breathe'
• UK 'can cut emissions to nearly zero'

One way this will be achieved is through the different perspectives OCO-2 and OCO-3 will get.

The former flies around the entire globe in what's termed a sun-synchronous polar orbit, which leads to it seeing any given location at the same time of day.

The latter, on the other hand, because it will fly aboard the station, will only see locations up to 51 degrees North and South; and see them at many different times of day.

That's interesting because plants' ability to absorb CO2 varies during the course of daylight hours. OCO-3's dataset will therefore have much to add to that of its predecessor.

"Getting this different time of day information from the orbit of the space station is going to be really valuable," Nasa project scientist Dr Annmarie Eldering told BBC News.

"We have a lot of good arguments about diurnal variability: plants' performance over different times of day; what possibly could we learn? So, I think that's going to be exciting scientifically."

Read more at BBC

Agência norte-americana avisa comunidades para que se prepararem para a mudança do clima

Trump assumiu a presidência prometendo desmontar a área ambiental do governo dos EUA, revogando regulações existentes e promovendo os combustíveis fósseis. Seu governo ocupou a Agência de Proteção Ambiental (EPA) com negacionistas e gente vinda do mundo do carvão e petróleo. Mas, pelo jeito, o desmonte não evitou que a EPA produzisse um documento de 150 páginas com um recado claro para a lida com as consequências dos desastres naturais que atingem o país: comecem a se planejar para a piora das catástrofes climáticas provocada pela mudança do clima. O documento dá recomendações sobre como lidar com os destroços e o entulho de enchentes, furacões e incêndios florestais. O Washington Post diz que o documento bate de frente com a retórica do diretor da própria EPA, Andrew Wheeler. No mês passado, Wheeler disse, em uma entrevista à CBS, que “a maioria das ameaças das mudanças climáticas ainda demorarão entre 50 a 75 anos para acontecer”. O jornal procurou sem sucesso a direção da EPA para que comentasse o documento.