6 Ways We’re Already Geoengineering Earth
- By Brandon Keim
- March 23, 2010 |
- 8:00 pm |
- Categories: Earth Science, Environment
Scientists and policymakers are meeting this week to discuss whether geoengineering to fight climate change can be safe in the future, but make no mistake about it: We’re already geoengineering Earth on a massive scale.
From diverting a third of Earth’s available fresh water to planting and grazing two-fifths of its land surface, humankind has fiddled with the knobs of the Holocene, that 10,000-year period of climate stability that birthed civilization.
The consequences of our interventions into Earth’s geophysical processes are yet to be determined, but scientists say they’re so fundamental that the Holocene no longer exists. We now live in the Anthropocene, a geological age of mankind’s making.
“Homo sapiens has emerged as a force of nature rivaling climatic and geologic forces,” wrote Earth scientists Erle Ellis and Navin Ramankutty in a 2008 Frontiers in Ecology paper, which featured their redrawn map of the human-influenced world. “Human forces may now outweigh these across most of Earth’s land surface today.”
Draining the Rivers
Of all the fresh water accessible in lakes, rivers and aquifers — what scientists call “blue water” — humankind uses about one-third every year. A fourth of Earth’s river basins run dry before they reach the sea.
At local scales, this changes weather patterns. The Three Gorges Dam on China’s Yangtze River for example, seems to be causing temperatures in its valley to drop, which in turn reduces rainfall. The draining of Kazakhstan’s once-vast Aral Sea has made regional temperatures hotter in summer and colder in winter, and rain now rarely falls.
Whether regional changes in turn have global consequences remains to be seen.
Images: 1) Aral Sea in 2006/European Space Agency. 2) Aral Sea in 1973/U.S. Geological Survey.
I wish you guys would stop beating a dead horse. The fragment “With atmospheric levels of heat-trapping carbon dioxide higher than at any time in the last 15 million years,…” is only true because you picked a specific stop date. But there have been recurring periods in earth’s history where C02 has been dramatically higher. Not only that but CO2 has not been proven as the causative agent in global warming.
Yes, and the Earth was definitely much warmer about 4 billion years ago when there were no humans around.
All joking aside, the horse is not yet dead, but moribund, which is exactly the point of this article.
The National Academy of Sciences defines geoengineering as “options that would involve large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry.”
None of these meet this definition. This list would better be defined as “things we’re doing to the earth that will have bad consequences”
The key problems and fear of real geoengineering is that we may have unintended consequences to doing something we thought would be good.
Small examples of real geoengineering:
- using old ships and airplanes for reef growth
- small hurricane thwarting tests
- (maybe) green roof tops
- (maybe) reforestation efforts
I say maybe here only because if you replace something man made with what was already there, then I am not sure it counts as real geoengineering.
I’m surprised only 12% of land is devoted to crops as stated in Infinite Farm. Everytime I fly it seems that cultivated land goes from horizon to horizon. Of course I doubt if that figure includes forests which in much of the US really are crops in that they are harvested on regular basis for wood. Just shows how much land must be desert, mountain, tundra etc.
@joelsapp:
The great Brandon Keim cannot be bothered with little details such as ~facts~ or ~definitions~
As long as the story fits his agenda of climate sensationalism, up it goes.
@joelsapp
The definition might be that but it is also a really new word. New words tend to change in meaning. I guess geoengineering does have an ‘intent’ aspect to the word, a feeling I guess. However if you think about it all life does this. We’d not be in this environment (or at all) with out all the stuff before us. They had no clue what they were doing to the world.
I guess one could look at that and say we shouldn’t worry as we had no idea what we were doing too. However I think as the first known species to see what we’ve done and understand it, maybe we might want to undo some of our changes.
@JohnMc
Who pays you? What is your degree in?
As a note:
Most of the species that changed the world ended up going extinct or changing along with it. Are we all right with being something other than human or dead?