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: Soft, energy-efficient robotic wings

Related Stories

A song of fire and ice in the ocean

Feb 10, 2015

Cyclic changes in the tilt of the Earth's axis and the eccentricity of its orbit have left their mark on hills deep under the ocean, a study published in Science has found.

Planets orbiting red dwarfs may stay wet enough for life

Feb 09, 2015

Small, cold stars known as red dwarfs are the most common type of star in the Universe, and the sheer number of planets that may exist around them potentially make them valuable places to hunt for signs of ...

Recommended for you

CERN researchers confirm existence of the Force

5 hours ago

Researchers at the Large Hadron Collider just recently started testing the accelerator for running at the higher energy of 13 TeV, and already they have found new insights into the fundamental structure ...

Soft, energy-efficient robotic wings

23 hours ago

Dielectric elastomers are novel materials for making actuators or motors with soft and lightweight properties that can undergo large active deformations with high-energy conversion efficiencies. This has ...

Super sensitive measurement of magnetic fields

Mar 30, 2015

There are electrical signals in the nervous system, the brain and throughout the human body and there are tiny magnetic fields associated with these signals that could be important for medical science. Researchers ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.