Climate alarmists and IPCC believe that the thermal response to increasing CO2 has a positive feedback from the increasing water vapor that results from higher ocean temperatures, melting permafrost releasing Methane and melting of the polar ice caps. All this leads to much higher temperatures. Current climate model averages indicate a temperature rise of 4.7 C by 2100 if nothing is done, 4.65 C if U.S keeps all its Paris commitments and 4.53 C if all countries keep their part of the agreement. In all cases, with or without Paris agreement we are headed for a disaster of biblical proportions.
As the chart indicates, implementing all of the Paris agreement will delay the end of mankind as we know it by at most 4 years.
Myself and quite a few scientists, meteorologists and engineers believe the feedback loop in nature is far more complicated than that, in fact, there is a large negative feedback in the system, preventing a temperature runaway, and we have the observations to prove it. The negative feedback manifests itself in 2 ways:
Inorganic feedback, represented by clouds. If there were no clouds, the tropics would average a temperature of 140 F thanks to the greenhouse effect. The clouds reflect back up to 300 W/m2 into space rather than the same energy being absorbed into water or soil. Clouds are highly temperature dependent, especially cumulus and cumulonimbus clouds. The figure below shows temperatures at the equator in the Pacific Ocean.
Cumulus clouds are formed in the morning, earlier the warmer it is, and not at all if it is cold, thunderstorms appear when it is warm enough. The figure shows how temperature in the equatorial Pacific rises until about 8:30 a.m, then actually declines between 9 and 12 a.m. even as the sun continues to rise. The feedback, which was positive at low temperatures becomes negative at warmer temperatures, and in the equatorial doldrums, surface temperature has found its equilibrium. No amount of extra CO2 will change that. Equatorial temperatures follow the temperature of the ocean, warmer when there is an el niño, cooler when there is a la niña. Here is a chart of temperature increases since satellite measurements began as a function of latitude.
Not so at the poles. the temperature record indicate a noticeable warming with large spikes up and down, up to 3 degree Celsius difference from year to year, especially the Arctic. So, how much has the Arctic melted? Here is a chart of Arctic ice cover for 31 May for the last 39 years.
If this trend continues, all ice may melt altogether in May in 300 to 400 years, faster if there is further warming and nothing else is changing. Let’s take a look at the Arctic above the 80th latitude, an area of about 3,85 million square kilometers, less than 1% of the earth’s surface, but it is there where global warming is most pronounced. Here are two charts from the last 2 years, ending with Sep 23 2019. (Source: Danish Meteorological Institute.)
We see clearly that the winter temperatures are rising at the poles, but the summer temperatures have remained steady ore below average year after year.
Something else must be going on. Take a look at the fall snow cover in the northern hemisphere: (Thanks, Rutgers Global Snow lab)
Yes the fall snowfall is increasing with increasing CO2!
The counter-intuitive conclusion is that it may very well be that warmer temperatures produces accumulation of snow and ice, colder temperatures with less snow accumulate less. What happens during the short Arctic summer? With more snow accumulated it takes longer to melt last years snow, so the temperature stays colder longer. This year the Arctic temperature has been running colder than normal every day between early June and late August. If this melting period ends without melting all snow, multi year ice will accumulate, and if it continues unabated, a new ice age will start.
The second feedback loop is organic. More CO2 means more plant growth. According to NASA there has been a significant greening of the earth, more than 10% since satellite measurements begun. This results in a cooling effect everywhere, except in areas that used to be treeless where they have a warming effect. The net effect is that we can now feed 2 billion more people than before without using more fertilizer. Check this picture from NASA, (now they can publish real science again) showing the increased leaf area extends nearly everywhere.
In addition, more leafs changes the water cycle, increases evapotranspiration, but, ant that is the good news, with more CO2 photosynthesis works better even in droughts, and more trees and vegetation reduces erosion and unwanted runoff. Good news all around.
In short, taking into account the negative feedback occurring, the earth will warm up less than 0.5 degrees with a doubling of the CO2 content, not at all in the tropics, and less than 6 degrees at the poles. Without the Paris agreement there will be no increase in the death rates in the cities, except from the slight increase of city temperatures due to the urban heat effect. With the Paris agreement we will have to make draconian cuts in our use of electricity, meaning using much less air conditioning and even less heating, and life expectancy will decline.
We need energy. It takes a lot of energy to clean up the planet. Developing nations should be encouraged to use electricity rather than cooking by dried cow-dung. Coal is limited, and we should leave some for our great great grandchildren. Oil and gas should be preserved for aviation, since there is no realistic alternative with a high enough energy density. Therefore I am an advocate for Thorium based nuclear energy, being safer than Uranium based nuclear energy, and, properly implemented will produce about 0.01% of the long term radioactive waste compared to conventional nuclear power plants. And there is a million year supply of Thorium available. Once the electricity power plants have fully switched away from coal and gas, then and only then is it time to switch to electric cars, since they will until then have to be recharged by electricity generated from coal. https://lenbilen.com/2017/07/14/twenty-five-reasons-to-rapidly-develop-thorium-based-nuclear-power-generation/