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FMP The wild card.

  • HildeMaassen
  • Aug 14, 2020
  • 6 min read


The cloud problem is:


“the wild card of climate change.”


The National Science Foundation




For decades it was hard to simulate and predict weather and clouds. In 2012 scientist said that they were starting to be able to make models that where useful in predicting processes.


That was the first time that scientists realised that clouds have a much greater impact on regional climate than realised before. On the basis of the new picture, they came to the conclusion that human pollution could be causing these climate disruptions instead of having a natural cause.


The prediction speed of the melting ice up to that moments were not right. Adding the new cloud models in the mix make them much better. The gauzy clouds allow more sunlight through in the summer, which melts more ice and exposes more sea and land surfaces; these effects are enhanced by deposition of dark aerosol (= mist, fog, dust) particles on the snow.


the new atmospheric model predict a 4 °C rise in global temperatures by the end of this century, whereas the previous model showed a 3.1 °C increase.


In 2014

There are a lot of unknowns in predicting the climate change and one of them is the behavior of the clouds in a warmer world.


According to Steven Sherwood of Australia’s Centre for Excellence for Climate System Science at the University of New South Wales. If carbon emissions are not reduced, then by 2100 the world will have warmed by 4°C (7.2°F) and up to 8°C in 2200.


More heat means more evaporation. That could result in more cloud cover. Low-hanging clouds reflect sunlight back into space, helping to cool the earth a bit.


But if more water vapor resulted in less cloud cover, more sunlight would reach the surface and the earth would warm more. Until now, it was predicted that high clouds would dampen global warming, but this new research shows that this does not have to be the case; it could do the opposite.


In 2016

New studies has been published. 25 years of actual cloud data is researched. That way scientists were able to see that cloud patterns have been shifting toward the poles and the tallest cloud tops have grown taller. The result of this is, among other things, the drying up of places in the subtropics such as California, South Africa and Southern Europe and a net warming of the planet.


Clouds play a role in cooling and heating the Earth - by reflecting solar radiation back into space on the one hand, but trapping solar energy in their structures on the other. As a result, clouds are one of the most important variables in the climate. The complex behavior of clouds has been one of the biggest areas of uncertainty for scientists trying to understand the current climate and predict future trends.


Cloud changes cause the earth to absorb more sunlight and that less radiation is reflected back into space, resulting in additional global warming due to increasing greenhouse gas concentrations. Scientists expect this trend in cloud behavior to continue in the future


Cloudpatterns.- Image: NASA Goddard Space Flight Center

This NOAA/NASA image shows Earth using near-infrared and shortwave infrared energy instead of the standard red, green, and blue light that the human eye has evolved to detect. By using infrared energy rather than visible light, the colors indicate differences in temperature rather than what they look like. For example, instead of appearing just white, clouds are shades of yellow, orange, and red depending on their elevation. Photograph: HANDOUT/AFP/Getty Images


2018

Noctilucent clouds "night shining clouds". As a result of human activities and the resulting increased water vapor in the Earth's atmosphere, glittering clouds at high altitudes become more visible. The results suggest that these strange but increasingly frequent clouds, visible only on summer evenings (most likely between June 15 and July 15 in the Netherlands), are an indicator of man-made climate change. Before the industrial revolution, the chances of seeing bright shining night clouds were only once every 100 years. Now we actually see them every year and this summer for several days. This is probably due to the increase in methane concentrations in the atmosphere.


Foto by Adrie Huiskamp. 2017. De Bilt, The Netherlands, Noctilucent clouds

Carbon dioxide warms Earth's surface and the lower part of the atmosphere, but actually cools the middle atmosphere where noctilucent clouds form. In theory, this cooling effect should make noctilucent clouds form more readily.


The reasons for this increased visibility were surprising. Carbon dioxide heats the Earth's surface and the lower part of the atmosphere. However, the middle part is cooled and these nocturnal clouds form there. Water vapor in the middle atmosphere comes from two sources: water vapor from Earth's surface that is transported upward, and methane, a potent greenhouse gas that produces water vapor through chemical reactions in the middle atmosphere. More water vapor in the middle atmosphere is making ice crystals larger and noctilucent clouds more visible.


2019

New research shows that more CO-2 causes more turbulence in the clouds and because the greenhouse effect makes the atmosphere warmer and therefore more humid, the clouds are less efficient from above. When cooling becomes less effective, stratocumulus clouds become thin. Their simulation in the research showed that the clouds fall apart and thus disappear when the CO2 content exceeds 1,200 parts per million. Which results in further global warming. At best, those 1200 particles will be reached in 100 years is stated. I wrote about this before: https://maassen3.wixsite.com/blog/post/ic-w9-articles-disappearing-clouds


2020

Clouds act as the sunscreen for the earth. New cloud models suggests global warming effect is underestimated. More studie is needed especially testing the results of the climate models against observations and understand the physics of the amplifying effect of clouds.



Conclusion

Examining clouds and the effect they have on climate change is difficult because clouds are difficult to simulate. How they move is quite unpredictable. Partly because they act very locally, complex. Whether they absorb, reflect or retain heat depends on the height, the thickness and the time of day or night. Only since 2014 have the models simulating clouds for research been adequate enough to be able to draw conclusions from them. Showing that clouds play a much greater role than previously expected.


Clouds are changing and they are moving towards the poles. If the CO2 content is too high, they can even dissolve completely, according to the latest studies. What this can mean in practical terms for global warming is not entirely predictable at the moment, but so far everything indicates that the earth will become 4 degrees warmer in this century. The better we can investigate the clouds, the worse the predictions. Just for comparison: during the Ice Age the earth was on average only 4 degrees colder than now !!


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© 2019 by Hilde Maassen 

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