If you have ever been on a tropical island, you may have experienced that as the sun rises, the temperature shoots up, only to start falling a few hours later due to the formation of clouds. Then, after increasing again for a few hours, the temperature peaks in the early afternoon, followed by cooling rain. It happens every day all over the tropics, but the climate models do a lousy job in reproducing this weather pattern.
The Iris Effect
One of the first serious attempts to understand cooling mechanisms in the tropics was Dr. Richard Lindzen’s proposed “iris effect” in 2001. He and his colleagues presented evidence that elevated sea surface temperatures caused fewer cirrus clouds, leading to heat radiation leaking out into space, thereby cooling the planet.
Those who believe some great climate catastrophe is on the way quickly labeled this “debunked,” but over the years, more papers supporting the theory have emerged.
The Thunderstorm Thermostat
Independent scientist and longtime resident in the tropics, Willis Eschenbach, has a different take on the same phenomenon. He noted a strong connection between warm tropical days and cooling in the days that followed, which can be explained almost entirely by thunderstorms that block the sun, dry the atmosphere, and allow radiation to escape. Below a sea surface temperature of 26°C, practically no thunderstorms form. Once the temperature hits this threshold, clouds rapidly gather and aggregate into rain-heavy mega-clouds that quickly cool a region with showers.
Eschenbach’s point is that the ocean is a temperature-triggered cloud-generating machine, and the climate models are largely blind to it.
The climate models predict that there should be a strong warming signal in the tropical troposphere, far up above the clouds. But there isn’t. There is no noticeable warming at all, which likely means that something is drying the atmosphere, and it must be a mechanism so powerful that it cancels the entire manmade greenhouse effect in that area.
From this, we can conclude that the models have a long way to go before they can predict the climate.