Scientists have examined records of cloud patterns from last three decades to reveal that the changes in the patterns match those predicted by climate model simulations thereby confirming climate change.
Researchers explain that data collected by satellites meant for monitoring weather is full of erroneous variability owing to a range of factors including changes in satellite orbit and instrument calibration among other things. To obtain error free data, researchers used a new technique to remove the variability from the records.
Analysis of this corrected data that shows of large-scale patterns of cloud change between the 1980s and 2000s indicates that the results are consistent with climate model predictions, including poleward retreat of mid-latitude storm tracks, expansion of subtropical dry zones and increasing height of the highest cloud tops.
Published in journal Nature, the study led by Scripps Institution of Oceanography brings to the fore first reliable evidence that changes in cloud patterns are the same as were predicted by climate models and that these changes are actually happening thereby signalling towards climate change.
Clouds substantially impact Earth’s energy budget by reflecting solar radiation back to space (the albedo effect) and by restricting emission of thermal radiation to space. Most of the uncertainty in how much the planet will warm in response to greenhouse gas emissions is due to uncertainty in how clouds will respond and impact Earth’s energy budget.
The authors also were able to assess the causes of the observed cloud trends using a variety of climate model simulations with and without influences of humans, volcanoes and other factors. The scientists expect the cloud trends to continue in the future as the planet continues to warm due to increasing greenhouse gas concentrations.