The silliest arguments, freshly baked by Senator Malcolm Roberts

One of the silliest arguments of climate deniers goes like this: the atmosphere with its greenhouse gases cannot warm the Earth’s surface, because it is colder than the surface. But heat always flows from warm to cold and never vice versa, as stated in the second law of thermodynamics.

The freshly baked Australian Senator Malcolm Roberts has recently phrased it thus in his maiden speech:

It is basic. The sun warms the earth’s surface. The surface, by contact, warms the moving, circulating atmosphere. That means the atmosphere cools the surface. How then can the atmosphere warm it? It cannot. That is why their computer models are wrong.

This is of course not only questions the increasing human-caused greenhouse effect, but in general our understanding of temperatures on all planets, which goes back to Joseph Fourier, who in 1824 was the first to understand the importance of the greenhouse effect.

Read the piece from Real Climate - “Can a blanket violate the second law of thermodynamics?”

Planes and planet-warming pollution

Airplanes could generate 43 gigatonnes of planet-warming pollution through 2050, consuming almost 5 percent of the world’s remaining carbon budget, according to a new Center report.

Aircraft emit staggering amounts of CO2, the most prevalent manmade greenhouse gas. In fact they currently account for some 11 percent of CO2 emissions from U.S. transportation sources and 3 percent of the United States’ total CO2 emissions. All told, the United States is responsible for nearly half of worldwide CO2 emissions from aircraft.

In addition to CO2, aircraft emit nitrogen oxides, known as NOx, which contribute to the formation of ozone, another greenhouse gas. Emissions of NOx at high altitudes result in greater concentrations of ozone than ground-level emissions. Aircraft also emit water vapor at high altitudes, creating condensation trails or “contrails" — visible cloud lines that form in cold, humid atmospheres and contribute to the warming impacts of aircraft emissions. The persistent formation of contrails is associated with increased cirrus cloud cover, which also warms the Earth’s surface. Aircrafts’ high-altitude emissions have a greater global warming impact than they would if the emissions were released at ground level.

Read the Centre for Biological Diversity story - “Aircraft emit staggering amounts of CO2, the most prevalent manmade greenhouse gas.”

Cloud analysis suggests climate change worse than thought

Cloud analysis by Yale University suggests
climate change much worse than imagined.

Climate change projections have vastly underestimated the role that clouds play, meaning future warming could be far worse than is currently projected, according to new research.

Researchers said that a doubling of carbon dioxide in the Earth’s atmosphere compared with pre-industrial times could result in a global temperature increase of up to 5.3C – far warmer than the 4.6C older models predict.

The analysis of satellite data, led by Yale University, found that clouds have much more liquid in them, rather than ice, than has been assumed until now. Clouds with ice crystals reflect more solar light than those with liquid in them, stopping it reaching and heating the Earth’s surface.

Read The Guardian story - “Global warming may be far worse than thought, cloud analysis suggests.”

Intense heat events becoming more frequent

Extreme heat events will be
annual occurrences by 2075.

Heatwaves that used to arrive once every 20 years or so could become annual events by 2075 across almost two-thirds of the planet’s land surface – if humans go on burning ever more fossil fuels and releasing ever more greenhouse gases.

Claudia Tebaldi, visiting scientist at the US National Centre for Atmospheric Research, and Michael Wehner, senior staff scientist at the Lawrence Berkeley National Laboratory, report in Climatic Change journal that stringent emissions reductions could reduce the risk of such extreme heat events.

But, even so, by 2075, an estimated 18% of the Earth’s surface could still experience those once-rare extreme heat events every year.

Read the Climate Home story - “Intense heatwaves could become ‘annual events’ by 2075.”