It was in 1985 that a researcher called Atsumu Ohmura who was checking levels of recorded sunlight around Europe found that it appeared to be too dark relative to levels of sunshine recorded by scientists in the 1960s. He found that solar radiation levels hitting the Earth’s surface had gone down by more than 10% in 30 years. And yet, by the 1980s evidence that the Earth was getting hotter was indisputable, so the reduction of solar radiation did not fit in with this idea.
This effect is now known as “global dimming and records show that the average amount of sunlight reaching the Earth has gone down around 3% every ten years. The effect is too small to be seen but it has long-term implications for climate change to the usefulness of solar power and even to the .ecological impact of photosynthesis by plants. What causes Global Dimming? It appears that pollutant air particles from fossil fuel burning make clouds reflect a greater percentage of the sun’s rays back into space.
Some scientists believe that global dimming was responsible for the droughts in Ethiopia in the 1970s and 1980s where millions of the population died due to the oceans in the northern hemisphere were not warm enough to allow rain to fall. Cleaning up global dimming pollutants without restricting greenhouse gas emissions can lead to a rapid warming effect causing health hazards to human health (such as the impact of unusual heat waves).