For a long time I've had a sort of implicit optimism that humanity will eventually figure shit out and we'll more or less be okay, but that for the time being, things were seriously screwed up. Over the last year or so though, I've started having a nagging voice in my head suggesting that, in fact, we have passed some kind point of no return, and that environmental catastrophe is essentially a foregone conclusion, with no amount of changing behavior able to stop it. Recently, I learned that the nagging voice is correct. NOVA taught me about global dimming:
...Fossil fuel use, as well as producing greenhouse gases, creates other by-products. These by-products are also pollutants, such as sulphur dioxide, soot, and ash. These pollutants however, also change the properties of clouds.
Clouds are formed when water droplets are seeded by air-borne particles, such as pollen. Polluted air results in clouds with larger number of droplets than unpolluted clouds. This then makes those clouds more reflective. More of the sun’s heat and energy is therefore reflected back into space.
This reduction of heat reaching the earth is known as Global Dimming...
Clouds are formed when water droplets are seeded by air-borne particles, such as pollen. Polluted air results in clouds with larger number of droplets than unpolluted clouds. This then makes those clouds more reflective. More of the sun’s heat and energy is therefore reflected back into space.
This reduction of heat reaching the earth is known as Global Dimming...
...Global Dimming is hiding the true power of Global Warming
The above impacts of global dimming have led to fears that global dimming has been hiding the true power of global warming.
Currently, most climate change models predict a 5 degrees increase in temperature over the next century, which is already considered extremely grave. However, global dimming has led to an underestimation of the power of global warming.
Addressing global dimming only will lead to massive global warming
Global dimming can be dealt with by cleaning up emissions.
However, if global dimming problems are only addressed, then the effects of global warming will increase even more. This may be what happened to Europe in 2003.
In Europe, various measures have been taken in recent years to clean up the emissions to reduce pollutants that create smog and other problems, but without reducing the greenhouse gas emissions in parallel. This seems to have had a few effects:
This may have already lessened the severity of droughts and failed rains in the Sahel.
However, it seems that it may have caused, or contributed to, the European heat wave in 2003 that killed thousands in France, saw forest fires in Portugal, and caused many other problems throughout the continent.
The documentary noted that the impacts of addressing global dimming only would increase global warming more rapidly. Irreversible damage would be only about 30 years away. Global level impacts would include:
The melting of ice in Greenland, which would lead to more rising sea levels. This in turn would impact many of our major world cities
Drying tropical rain forests would increase the risk of burning. This would release even more carbon dioxide into the atmosphere, further increasing global warming effects. (Some countries have pushed for using “carbon sinks” to count as part of their emission targets. This has already been controversial because these store carbon dioxide that can be released into the atmosphere when burnt. Global dimming worries increase these concerns even more.)
These and other effects could combine to lead to an increase of 10 degrees centigrade in temperature over the next 100 years, not the standard 5 degrees which most models currently predict.
This would be a more rapid warming than any other time in history, the documentary noted. With such an increase,
Vegetation will die off even more quickly
Soil erosion will increase and food production will fail
A Sahara type of climate could be possible in places such as England, while other parts of the world would fare even worse.
Such an increase in temperature would also release one of the biggest stores of greenhouse gases on earth, methane hydrate, currently contained at the bottom of the earth’s oceans and known to destabilize with warming. This gas is eight times stronger than carbon dioxide in its greenhouse effect. As the documentary also added, due to the sheer amounts that would be released, by this time, whatever we would try to curb emissions, it would be too late.
“This is not a prediction,” the documentary said, “it is a warning of what will happen if we clean up the pollution while doing nothing about greenhouse gases.”
The above impacts of global dimming have led to fears that global dimming has been hiding the true power of global warming.
Currently, most climate change models predict a 5 degrees increase in temperature over the next century, which is already considered extremely grave. However, global dimming has led to an underestimation of the power of global warming.
Addressing global dimming only will lead to massive global warming
Global dimming can be dealt with by cleaning up emissions.
However, if global dimming problems are only addressed, then the effects of global warming will increase even more. This may be what happened to Europe in 2003.
In Europe, various measures have been taken in recent years to clean up the emissions to reduce pollutants that create smog and other problems, but without reducing the greenhouse gas emissions in parallel. This seems to have had a few effects:
This may have already lessened the severity of droughts and failed rains in the Sahel.
However, it seems that it may have caused, or contributed to, the European heat wave in 2003 that killed thousands in France, saw forest fires in Portugal, and caused many other problems throughout the continent.
The documentary noted that the impacts of addressing global dimming only would increase global warming more rapidly. Irreversible damage would be only about 30 years away. Global level impacts would include:
The melting of ice in Greenland, which would lead to more rising sea levels. This in turn would impact many of our major world cities
Drying tropical rain forests would increase the risk of burning. This would release even more carbon dioxide into the atmosphere, further increasing global warming effects. (Some countries have pushed for using “carbon sinks” to count as part of their emission targets. This has already been controversial because these store carbon dioxide that can be released into the atmosphere when burnt. Global dimming worries increase these concerns even more.)
These and other effects could combine to lead to an increase of 10 degrees centigrade in temperature over the next 100 years, not the standard 5 degrees which most models currently predict.
This would be a more rapid warming than any other time in history, the documentary noted. With such an increase,
Vegetation will die off even more quickly
Soil erosion will increase and food production will fail
A Sahara type of climate could be possible in places such as England, while other parts of the world would fare even worse.
Such an increase in temperature would also release one of the biggest stores of greenhouse gases on earth, methane hydrate, currently contained at the bottom of the earth’s oceans and known to destabilize with warming. This gas is eight times stronger than carbon dioxide in its greenhouse effect. As the documentary also added, due to the sheer amounts that would be released, by this time, whatever we would try to curb emissions, it would be too late.
“This is not a prediction,” the documentary said, “it is a warning of what will happen if we clean up the pollution while doing nothing about greenhouse gases.”
Good God, we're through.
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