Climate change and sustainable energy - John Houghton

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We are already committed to a 2 deg C increase in global average temperatures. The climate change consequences will include lethal heatwaves, devastating floods and droughts, steady rises in sea levels and disruption to the Gulf Stream. To avoid worse, we immediately need a global energy strategy - otherwise, with technology as the engine, the market as the propellor, but without strategy as a rudder, we might all end up in New Orleans.

An affordable portfolio of possible actions to reduce carbon dioxide emissions over the next 50 years, which combine to avert the worst of global climate change:

• Buildings - increase energy efficiency by 25%
• Double vehicle fuel efficiency
• Capture C02 from 800 GW of coal burning power stations
• Reverse tropical deforestation by 300 Mha
• 2000 GW of wind power.
• 150 km2 of solar PV.
• Biofuels from 200Mha.

(the last three to replace equivalent fossil fuel burning).

• Atmospheric carbon dioxide (CO2) levels were stable at around 280 parts per million (ppm) for most of the past 1000 years.
• Unrestrained burning of fossil fuels will produce 600+ ppm by 2100, leading to global average temperature rises of up to 6 deg C.
• The difference between the middle of an ice age, and an interglacial, is 6 deg C.
• The first 8 months of 1998 were globally each the warmest on record for that month.
• Over 20,000 people died in central Europe due to the heat wave in summer 2003.
• By 2100, the summer 2003 maximum temperature will be a cool year.
• Greenland will melt if the temperature rises more than 3 deg C, taking 1000 years, adding 7 m to global sea levels.
• Fresh water from melting ice threatens the Thermo-Haline Circulation (THC) - the Gulf Stream could shut down.
• The THC has shut down in the past.
• Despite improved growing conditions at high northern latitudes, the adverse effects of global climate change will dominate increasingly as global average temperatures rise.
• Climate change scientists agree that the world will suffer greatly if CO2 levels rise above 450 ppm.
• IPCC and UK Government Treasury economists calculate that the cost to the world economy of stabilizing CO2 at 450 ppm would be the equivalent of slowly growth by six months over the course of 50 years.


John Houghton is a former chair of the Intergovernmental Panel on Climate Change. He has been giving numerous public lectures this year on "Climate change and sustainable energy", a version of which has been published by the Royal Meteorological Society (PDF).