OSB archive
OSB archive

Weeds get high on carbon dioxide

Pete Wilton

Every so often the New York Times comes up with a firecracker of a science piece: as evidenced by this NYT article by Tom Christopher on weeds and climate change.

It's like a written version of those nesting Russian dolls with many fascinating layers but one of the big headlines is: 'weeds benefit far more than crop plants from changes in CO2 and that the implications of this for agriculture and public health are grave.'

US Department of Agriculture researchers testing urban plots resembling the hot CO2-rich future conditions of many parts of the world discovered an 'ecology on amphetamines' with the city-weeds far out-stripping their country cousins.

In what's worse news for hay-fever sufferers plants such as ragweed produce twice as much pollen with more of the allergy-producing protein when exposed to higher levels of CO2.

Many weeds are already taking over (as the Kudzu-ridden field in Mississippi shown above demonstrates) as human activity accelerates climate change. So should we spray, burn and decimate our weedy friends?

Science yields another surprise: removing these interlopers doesn't bring back native plants, it causes the ecosystem to crash: suggesting that many weeds are 'passengers' simply exploiting new ecological niches opened up by climatic change rather than driving the extinction of native plants.

Instead, Chris suggests, we could learn from weeds which, after all, provided the original basis for all our crops: much as Oxford scientists are looking to do to create salt-tolerant wheat and other crops. Like our Neolithic forebears we need to seize the opportunity presented by changing conditions to breed new types of plants that benefit man.

In short it's the message evolution teaches plants and animals alike; adapt or die.