Climate change: Climate change is not just about emissions, carbon dioxide or concerns about industrial output in the developed world.
It is a Third World development issue, given the additional numbers it will add to the world's hungry. Environmental change would expect to add another 50 million to the number of starving in the world.
A group of scientists discussed global biological change and sustainability yesterday at the BA Festival of Science, taking place at Trinity College Dublin. They painted a grim picture of how climate change is likely to affect the world's poorest countries.
There are already 500 million people around the world with too little food, said Prof Martin Parry of the UK Meteorological Office's Hadley Centre. "We expect climate change to aggravate the number of those at risk of hunger, probably to the tune of 50 million," he said. "The main issue is the greatest proportion of that is going to be in Africa. It is not just climate change, it is the number of people exposed to it."
For this reason climate change is a development issue that must be taken into consideration with other issues faced by the Third World.
The already agreed greenhouse gas reductions will do little to protect against increased starvation, Prof Parry suggested. "It will take huge emission reductions to avoid the risk of hunger, 20 times higher a reduction than Kyoto."
Even a 10-fold improvement on Kyoto is unlikely to help, he believes. "Maybe we should begin to meet the challenge of climate change as a development issue."
Findings by Prof Steve Long of the University of Illinois suggest the picture might be worse than predicted. "The grim scenario painted by Martin is possibly grimmer," he told the BA meeting.
Researchers have long thought that warmer temperatures and higher carbon dioxide levels might boost agricultural output by 10 to 20 per cent, Prof Long said. This appears not to be the case given novel field trials conducted by his group, however.
Plants use carbon dioxide, a key global warming gas, to grow and produce crops. Trials done in greenhouse settings suggested there would be a yield increase as carbon dioxide levels rose.
Prof Long developed a way to increase carbon dioxide levels in outdoor field trials as a way to test this hypothesis on a larger real-world scale. He found that the hoped-for increase was only half of what was expected for crops including rice, wheat, maize, sorghum and soybean. This means that food production losses caused by an overheated climate are less likely to be offset by higher carbon dioxide.
Another consequence of climate change will be higher ground level ozone levels and once again Prof Long's field trials showed that yields will suffer. Projected ozone levels by 2050 could reduce soybean yields by 20 per cent, his figures predict.
Applying these figures to food production capacity in Africa, yields there could fall by between 5 and 10 per cent by 2050, Prof Parry said.
Preventing climate change-induced hunger needed a different approach, according to Duncan McLaren of Friends of the Earth Scotland.
"Famine is not caused by a shortage of food, famine is caused by a shortage of justice," Mr McLaren said.