“Now the researchers propose that the record warmth was due to an abnormally low amount of the low-level cloud. Compared to high clouds, tops of the low-level clouds are warm, so they do not impede thermal radiation that much, but reflect a lot of sunlight thus contributing to net cooling.”
I’m confused about the moving parts here. Could you please explain? What happened with cloud cover and what would you expect to result from that?
“If we as a planetary community urgently develop an understanding of this complexity, and based on this understanding, protect the biosphere, we will likely fulfil our evolutionary mission as a thinking species.”
I couldn’t agree more, and this is so powerfully stated.
Thank you, Hart. Low clouds have relatively warm tops, from which a lot of thermal radiation is emitted to space. Thus they do not increase the greenhouse effect as much as high clouds, with cold tops, could. Thus when you reduce low clouds, the dominant effect is the decrease of albedo, i.e. warming.
I love that you are calling out a profound lack of science in current reporting. Another issue for the Amazon is the fires they had this year. There was no stopping them, it was horrific and surely that contributed to the loss of cloud cover.
Thank you, Kathryn. With fires, a prominent issue is that even when they are not set by people directly, still previous clearing disturbs the moisture regime, dries out the land surface and increases fire probability. Fires follow logging.
So where is mention about the hydrologic disaster still unfolding in Russian Siberia, closer to home. From the early 1950s into 1970s many of the major Siberian rivers were dammed and forced inland burying forests, tundra, and over permafrost. This was just the beginning of a hydrological alteration and weakening of the natural pumps- rivers historically flowing undetained directly into the Arctic Ocean and Kara Sea. The subarctic and Arctic used to be home to the largest amount of fresh water rivers flowing 24 x7 but by the 1970's many of these rivers were impounded behind dams for 6 months at a time.
Dear Anastassia,
I am eternally grateful for your work.
I have a question about this paragraph:
“Now the researchers propose that the record warmth was due to an abnormally low amount of the low-level cloud. Compared to high clouds, tops of the low-level clouds are warm, so they do not impede thermal radiation that much, but reflect a lot of sunlight thus contributing to net cooling.”
I’m confused about the moving parts here. Could you please explain? What happened with cloud cover and what would you expect to result from that?
“If we as a planetary community urgently develop an understanding of this complexity, and based on this understanding, protect the biosphere, we will likely fulfil our evolutionary mission as a thinking species.”
I couldn’t agree more, and this is so powerfully stated.
Thank you, Hart. Low clouds have relatively warm tops, from which a lot of thermal radiation is emitted to space. Thus they do not increase the greenhouse effect as much as high clouds, with cold tops, could. Thus when you reduce low clouds, the dominant effect is the decrease of albedo, i.e. warming.
In my opinion these two diagrams show nicely the climatic difference between high and low clouds https://earthobservatory.nasa.gov/features/Clouds/clouds4.php
I love that you are calling out a profound lack of science in current reporting. Another issue for the Amazon is the fires they had this year. There was no stopping them, it was horrific and surely that contributed to the loss of cloud cover.
Thank you, Kathryn. With fires, a prominent issue is that even when they are not set by people directly, still previous clearing disturbs the moisture regime, dries out the land surface and increases fire probability. Fires follow logging.
Thank You, Anastassia. I'm pleased to be able to subscribe to your blog.
So where is mention about the hydrologic disaster still unfolding in Russian Siberia, closer to home. From the early 1950s into 1970s many of the major Siberian rivers were dammed and forced inland burying forests, tundra, and over permafrost. This was just the beginning of a hydrological alteration and weakening of the natural pumps- rivers historically flowing undetained directly into the Arctic Ocean and Kara Sea. The subarctic and Arctic used to be home to the largest amount of fresh water rivers flowing 24 x7 but by the 1970's many of these rivers were impounded behind dams for 6 months at a time.