Читать книгу How Can I Stop Climate Change: What is it and how to help - Литагент HarperCollins USD, F. M. L. Thompson - Страница 86

The UK government, together with the rest of the European Union, has pledged to stabilise greenhouse gases to prevent average global temperatures rising more than 2°C above pre-industrial levels. Allow greater temperature change, climate scientists say, and we start to play havoc with agriculture, the economy and the natural environment – committing millions of people to hardship and millions of species to extinction. Perhaps even more worrying is the prediction that a higher rise than 2°C would increase the risk of spiralling and irreversible climate change.

UK path to a safer future

Steady but steep - the UK needs to make serious cuts in carbon dioxide emissions over the next 40 years to play its part in avoiding runaway climate change. Based on research by the Tyndall Centre for Climate Change Research at the University of Manchester, the chart assumes the need to stabilise atmospheric carbon dioxide at 450 ppm.

To stay within a 2°C rise the science tells us we would need to keep greenhouse gases (and other pollutants) at no more than 450 parts per million carbon dioxide equivalent. But we’re already racing towards that threshold: carbon dioxide alone had already reached 380 ppm in 2006, and emissions are rising by nearly 2 ppm per year.

And there’s more. As a result of the carbon dioxide already in the atmosphere scientists warn that 2°C could be the lowest increase we can hope for.

So how much time do we have to turn things around? Because carbon dioxide stays in the atmosphere for so long, and because it takes a while for it to affect the climate, the fossil fuel we burn in power stations today will still be affecting the climate at the start of the next century. That means we have to reduce emissions as quickly as possible, rather than hoping to make big cuts five years from now. The sooner we make cuts, the better.

Two facts illustrate the urgency of the task that faces us if we want to stay within a 2°C rise:

1 Greenhouse gas emissions have to start falling by 2015. They must then continue to decline.

2 Industrialised countries need to cut emissions by about 90 per cent by the middle of this century.

So can it be done? Some argue that it is unrealistic to expect to cut carbon emissions quickly and deeply enough to stay within 2°C. But the scientific consensus is that we must.