Carbon canaries (From York Press)

Carbon canaries

10:27am Friday 19th October 2007 in Letters By Reader's letter

CANARIES were once used to warn miners of a build-up of toxic gases. If the canary died, the miners got out as fast as they could.

Today, the Inuit people of the Canadian Arctic liken themselves to canaries, as they try to warn the world of the impact of global warming.

It is believed two degrees C of warming is already probable, as there is a delay in the link between CO2 levels and global temperature.

It is now recognised that CO2 and other greenhouse gases are the main drivers of temperature and hence climate change.

Other scientists warn of positive feedbacks that will cause runaway rise in temperatures if a 2C rise happens, so we may have already passed the tipping point. We need to deal with this situation.

It has been proposed to sprinkle iron over the ocean surface to cause algal bloom to absorb CO2.

However, the US fears the project would lead to toxic algae blooms, and that the decomposing plankton masses would release other greenhouse gases.

Professors Stephen Salter and John Latham have had one of the most ingenious ideas.

When a cloud takes up and condenses water vapor, the underside becomes blacker, and the top more shiny as it reflects light back into space.

Just as the poles stay cool because the white ice reflects back light, so the clouds, if water droplets were formed, could reflect more light and cool the earth.

Salter wishes to demonstrate whether this technique is feasible. It would cost little to carry out a trial, but the Government has not yet provided funds.

Will the impact of climate change unite us, or will we go down arguing about a few pounds and who owns the north-west passage and oil reserves?

Chris Clayton, Hempland Drive, York.