Stronger evidence for human origin of global warming

Jul 30, 2007

A recent statistical analysis strengthens evidence that human activities are causing world temperatures to rise. Most climate change scientists model Earth systems from the ground up, attempting to account for all climate driving forces. Unfortunately, small changes in the models can lead to a broad range of outcomes, inviting debate over the actual causes of climate change.

Physicist Pablo F. Verdes of the Heidelberg Academy of Sciences in Germany has found a way to avoid the subjective flaws of climate models by applying sophisticated analysis techniques to data from the past hundred and fifty years.

The approach mathematically stitches together known facts about the global climate into a more objective and coherent picture.

Verdes, now at Novartis Pharma, examined data on temperature anomalies, the strength of the radiation emitted from the Sun, and volcanic activity. The relatively recent increases in solar radiation, combined with reduced volcanic activity, contribute to the increase in world temperatures. However, Verdes' analysis demonstrates that these natural causes do not completely explain the observed warming.

Verdes calculated the amount of non-natural influence required to match the increases in temperature observed in the last 150 years. He plotted the influence over time. Then, he compared it to the evolution of greenhouse gasses, taking into account the cooling due to aerosols. With allowances for error, he found that influences attributable to greenhouse gasses mirror the graph of non-natural influence needed to explain the observed temperature increase of recent decades.

His research shows that, if you look at global warming as a puzzle, and you put together the natural factors such as increased solar radiation and reduced volcanic activity, a hole remains. The human factors of greenhouse gas and aerosol emission complete the picture.

Citation: Pablo F. Verdes, Physical Review Letters (forthcoming article)

Source: American Physical Society

Explore further: What is Nothing?

add to favorites email to friend print save as pdf

Related Stories

Tissue regeneration using anti-inflammatory nanomolecules

29 minutes ago

Anyone who has suffered an injury can probably remember the after-effects, including pain, swelling or redness. These are signs that the body is fighting back against the injury. When tissue in the body is damaged, biological ...

NASA sees Tropical Storm Karina get a boost

33 minutes ago

NASA's TRMM satellite saw Tropical Storm Karina get a boost on August 22 in the form of some moderate rainfall and towering thunderstorms in the center of the storm.

C2D2 fighting corrosion

35 minutes ago

Bridges become an infrastructure problem as they get older, as de-icing salt and carbon dioxide gradually destroy the reinforced concrete. A new robot can now check the condition of these structures, even ...

Recommended for you

What is Nothing?

20 hours ago

Is there any place in the Universe where there's truly nothing? Consider the gaps between stars and galaxies? Or the gaps between atoms? What are the properties of nothing?

On the hunt for dark matter

23 hours ago

New University of Adelaide Future Fellow Dr Martin White is starting a research project that has the potential to redirect the experiments of thousands of physicists around the world who are trying to identify the nature ...

Water window imaging opportunity

Aug 21, 2014

Ever heard of the water window? It consists of radiations in the 3.3 to 4.4 nanometre range, which are not absorbed by the water in biological tissues. New theoretical findings show that it is possible to ...

User comments : 0