CLOUDS
CONCLUSION
Does the increase in clouds accelerate global warming?
To summarize the conclusions of the hypothesis set before the study, it was not possible to quantitatively determine how much clouds affected accelerating global warming, but it was possible to guess that the positive feedback effects affected more strongly to the Earth than the negative feedback effects.
The rise in Earth's temperature is caused by various feedback processes between the atmosphere, the ocean, and the surface. Among them, albedo feedback and water vapor feedback processes have a positive feedback effect on temperature rise. On the other hand, cloud-radiation feedback may represent positive or negative feedback depending on the climate model, so research on this is still being actively conducted.
It is mainly analyzed through climate models by controlling the presence or absence of clouds in environmental conditions where carbon dioxide is increasing. The reason is that the cloud distribution increases the sensitivity of the climate model. In the absence of clouds, it is known that there is little difference in surface heating rates between radiation models used in climate models. The feedback results of cloud-radiation vary with changes in cloud distribution, such as the rise of the tropospheric interface, the rise of the high cloud layer, and the decrease of the mid or lower clouds, increasing the sensitivity of the climate model.
In particular, increasing carbon dioxide must be considered in order to understand the effects of clouds in the overall Earth system. It is known that as the amount of carbon dioxide in the atmosphere increases, the temperature of the troposphere and the surface increases due to the greenhouse effect, but the temperature of the stratosphere decreases. As a result, it was found that the width of the temperature lapse rate from the troposphere to the stratosphere decreased when the latent heat emission altitude was 500hPa in the cloudy sky than in the clear sky.
Clouds also affect the Earth’s temperature drop. Typically, there is a direct and indirect cooling effect of aerosol which is a type of cloud condensation nucleus. With a similar principle, it has been found that the material released by the increased Artic microalgae due to global warming acts as a condensation nucleus of clouds, affecting the cooling effect. In addition, depending on the location or type of cloud, the cooling effect may prevail over the atmospheric heating effect.
In this way, clouds form various positive feedback processes and negative feedback processes by interacting with various regions such as the hydrosphere and biosphere that make up the global environment. Through this work, it was not possible to find out the exact figures of how much each feedback process affects global warming or cooling. However, it must be clear that the average temperature of the Earth is rising every year.
Typically, looking at the temperature deviation map in 2019 compared to the average year from 1981 to 2010, it can be seen that the high temperature phenomenon is remarkable in almost all regions. Therefore, it could be inferred that the positive feedback processes had greater impacts on the Earth than the processes that affect cooling.
Further Research
A study on the exact figures of how much each feedback process affects the rise and fall of the Earth’s temperature has yet to be completed. Therefore, if research is conducted on how much each factor influencing global temperature is affected, research on ways to slow global warming will be further accelerated.