Global Dimming and Brightening Impact on Solar Radiation
In a special edition of the Journal of Geographical Research, the growing research field of global dimming has been reviewed in over twenty articles.
The phenomena of global dimming/brightening are thought to be caused by human activity and control solar radiation which acts on the Earth's surface and in turn influences the climate.
The investigation of the factors that result in the reduction or intensification of solar radiation, and in turn cause these phenomena, is still a growing field of research.
This special volume published by the American Geophysical Union has contributed significantly to climate science and provides a pool of knowledge on the subject.
The initial results of the study on global dimming/ brightening as a result of solar radiation on the Earth's surface were published in the late eighties and early nineties for specific regions on the Earth.
The studies revealed that solar radiation is not constant over time but actually varies significantly over decades.
It was only in 1998 that the first global study was conducted for larger areas such as the African, Asian, European and North American continents.
The phrase global dimming was coined in a paper published in 2005 to oppose the term global brightening which had been in use since 2001, for the previously established reduction in solar radiation.
For this study, researchers first investigated the link between global dimming/brightening and the carbon cycle.
They found that there is more scattered light present during the periods of global dimming because of the increased amounts of aerosols and clouds, which enables plants to absorb carbon dioxide more readily than when the air is clearer and cleaner.
It still remains unclear whether this phenomenon is triggered by clouds and aerosols, or even the interactions between clouds and aerosols, because aerosols are capable of influencing the lifespan of clouds.
The investigation of the link between these phenomena and aerosols and clouds is further compounded by the fact that there is insufficient observational data available on how clouds and aerosol loadings have been changing in the last decade.
A lot of research remains to be done on the magnitude of global dimming/ brightening and how these differ in urban and rural areas.
Scientists also need to incorporate the effects of this phenomenon more effectively into climate models so as to better understand climate change.
Studies indicate that this phenomenon masked actual rises in temperature until the eighties.
The phenomena of global dimming/brightening are thought to be caused by human activity and control solar radiation which acts on the Earth's surface and in turn influences the climate.
The investigation of the factors that result in the reduction or intensification of solar radiation, and in turn cause these phenomena, is still a growing field of research.
This special volume published by the American Geophysical Union has contributed significantly to climate science and provides a pool of knowledge on the subject.
The initial results of the study on global dimming/ brightening as a result of solar radiation on the Earth's surface were published in the late eighties and early nineties for specific regions on the Earth.
The studies revealed that solar radiation is not constant over time but actually varies significantly over decades.
It was only in 1998 that the first global study was conducted for larger areas such as the African, Asian, European and North American continents.
The phrase global dimming was coined in a paper published in 2005 to oppose the term global brightening which had been in use since 2001, for the previously established reduction in solar radiation.
For this study, researchers first investigated the link between global dimming/brightening and the carbon cycle.
They found that there is more scattered light present during the periods of global dimming because of the increased amounts of aerosols and clouds, which enables plants to absorb carbon dioxide more readily than when the air is clearer and cleaner.
It still remains unclear whether this phenomenon is triggered by clouds and aerosols, or even the interactions between clouds and aerosols, because aerosols are capable of influencing the lifespan of clouds.
The investigation of the link between these phenomena and aerosols and clouds is further compounded by the fact that there is insufficient observational data available on how clouds and aerosol loadings have been changing in the last decade.
A lot of research remains to be done on the magnitude of global dimming/ brightening and how these differ in urban and rural areas.
Scientists also need to incorporate the effects of this phenomenon more effectively into climate models so as to better understand climate change.
Studies indicate that this phenomenon masked actual rises in temperature until the eighties.