大象传媒

So what is climate change?

It's really driven by global warming, which is the process where greenhouse gases in the atmosphere, carbon dioxide being the main human-made one, keep the planet warm. If we didn't have them it would be -18潞C... pretty chilly!

So we do need greenhouse gases to keep us warm, but man's been increasing the amount of greenhouse gas in the atmosphere through the burning of fossil fuels - and we've seen about half a degree increase in global temperatures in the last century, particularly in the last 40 years or so. It's this warming of the planet which drives climate change.

As we see increased temperatures we see changes in rainfall patterns which can lead to droughts in some areas and floods in others. We see changes in intensity and frequency of severe weather events like hurricanes and storms, so a whole range of climate impact.

Dr Dave Reay

What evidence is there that we're warming up?

We've got reasonable records of what the temperature has been since about 1850, thanks to data from weather stations around the planet. These records show that the temperature has been going up and up. Now natural drivers of planet temperature like the activity of the sun, or volcanoes can affect temperature, but since the industrial revolution we've not been able to explain the increase in temperature by a natural occurrence, it's our greenhouse gas emissions which are the key culprit.

Can man really ever make as much damage and cause as much of an impact as one of these big natural events such as a volcano?

It's amazing to think that we can have any impact on the global climate. You think driving a car or getting a plane is not going to make much difference. But greenhouse gas concentration is higher than at anytime in the last 420,000 years and global temperatures are the highest for at least 1000 years.

How does pollution affect the planet?

The Nobel Laureate Paul Crutzen describes it as the 'Anthropocene', an age where rather than the planet controlling man's development and civilization - it's humankind which is actually making and driving the climate, so we're really in a completely new world as far as the environment goes.

So will we get to a point where we can't reverse what we've done?

Some people are very pessimistic and think we're already too late. There are different tipping points, for example; in the Amazon, the hotter it gets the drier it gets, and the Amazon represents a really big sink that breathes in a lot of carbon dioxide, so as it dries out the models predict that it will start producing carbon dioxide. This is a feedback effect where the carbon dioxide starts coming out, causes more warming, which causes more drying of the Amazon.

We're not sure exactly how warm we have to get for these feedback effects to take place, but we know they're there and we're always pushing up against this, and the warmer we get the higher the risk.

So tens of years, hundreds of years, or do we just not know?

To avoid dangerous climate change, to avoid these runaway effects, we need to keep global warming below about 2潞C. On current rates of emission, we'll see that kind of warming by 2030 - 2040, so the actual time we've got is very limited to actually do something about these greenhouse gas emissions we're putting out today.

Worst case scenario, and we don't do anything about it, are we going to see scenes like we got in the film 'The Day After Tomorrow'?

That's pretty unlikely... the idea behind that is that we see such a big melt of the Greenland ice sheet and polar ice cap that it actually stops the Gulf Stream that warms us up. It would need massive amounts of melt and we're not even sure there's enough ice there for that.

In a worst case scenario as far as our greenhouse emissions go, we could see 6潞C warming this century and that would have a devastating impact. By 2050 an extra 50 million people would be at risk of starvation, particularly in Africa. There would be huge migration caused by flooding. We're looking at a sea level rise of 80cm and that's going to have a huge impact on countries which don't have money to adapt and build higher sea walls. We're really playing with fire here.

So this is all pretty bad... What can we do about it? Tell us about the characters in your talk, Mr Carbone and Mrs Green...

Well I was really frustrated when George Bush withdrew from the Kyoto Protocol and it felt like the science wasn't really getting through to the politicians. Instead of carrying on being frustrated I thought I would look at what I could do as an individual, how I could cut my own emissions.

I thought it was going to be big business and industry which produced all these greenhouse gas emissions. But I was wrong. I found that a quarter of all our emissions in the UK come from transport, so there I could make a difference by how I travelled around - train instead of plane etc.

Then I found that another quarter of UK emissions were through home energy use. So again, by fitting low energy light bulbs, using efficient appliances I could make a difference there.

And the other half, that was big business and industry, but it was also whether I turned the lights off at work when I left, or turned my computer off and took part in the recycling scheme. So in all these areas I can actually make a difference.

That's what led to Mr Carbone... I wanted to do a scientific study about what impact an individual could have versus someone who didn't do anything. So Mr Carbone is someone who is climate ignorant and makes no effort to save energy. I compared him to someone who does make a difference by recycling and using public transport.

Do your bit by recycling

Over a lifetime I found that for Mr Carbone's lifestyle, where he made no effort to cut his emissions, he had this huge impact on climate. But Mrs Green cut her emissions by 1000 tonnes, made a huge difference to her climate impact AND saved 拢80,000 over her lifetime on things like fuel costs.

Wow! Well, put it to people that they can save 拢80,000 and I don't see how they could refuse!

Yes! And they're pretty small things like putting in low energy light bulbs... you cut emissions and save money too. I guess the key message to come out of it, was that none of these things are expensive, we're not talking about solar panels or anything like that, it was recycling and being more aware of energy wastage, switching off your TV instead of leaving it on standby etc... It really makes a difference.

If you multiply the energy savings from an individual by streets and towns, you're looking at a cut in greenhouse gas emissions from the developed world equal to six Kyoto Protocols! It really brings home the power of the individual when people act en masse.

Wind turbines

So what should people do if they feel really strongly about this?

Well if we're doing these things at home we can ask our MP 'why aren't you doing it'? We can ask the political party we're voting for 'what's your position on climate change? How are you going to tackle this problem? Are you going to provide good public transport facilities, good recycling schemes'... We can put pressure on them to provide these things.

It's easy to e-mail your MP or MEP. Make them aware that as constituents we're concerned about it and want them to help us tackle it.

And as a consumer, we can put pressure on manufacturers. Set-top boxes are a good example - we have one that has no off button, it's on standby by default, we have to turn it off at the plug. It's consumer pressure which will lead them to put these buttons on, people demand it.

In shops, providing more local produce, providing re-usable bags, those kinds of things, we have power to put that pressure on them. It's where this bottom-up effect really starts to have a huge impact.

And finally, are you taking part in the 大象传媒's Climate Change experiment?

Absolutely! It's really going to help reduce the uncertainty about the range of temperatures that we could see as a result of global warming. It will enable us to give more precise predictions.

For more information on the Science Festival, climate change and Dave Reay's work follow the links below: