• Question: there's a massive change in climate these days due to global warming and in the Arctic the ice caps are melting, causing a rise in sea levels, what else can we do to try and reverse this happening

    Asked by littlemisstiger to Nuala, James P on 3 Jul 2012.
    • Photo: Nuala Carson

      Nuala Carson answered on 3 Jul 2012:

      Hey littlemisstiger,

      Is your question what can we do to stop the ice in the Arctic and Antarctic melting?

      Its a pretty complicated question to address, which is why so much research is currently ongoing into how we might protect the polar regions. We do need to protect them as they are so important as unique habitats, but also the role they play in controlling global temperature. The problem is that we are increasing the earths temperature, which is causing ice melt, which in turn causes further temperature rise – so the whole processes is accelerating (not good!).

      In a broad sense the best thing we can do it to change people attitudes to the use of fossil fuels, and addition of carbon dioxide to the atmosphere. If everyone in the world thought and acting a little more ‘green’ then we would be well on our way to protecting them.

      Some people are worried that we may have already gone to far to stop them melting through social change, and are now starting to think about what we call ‘geoengineering’ solutions. These are man made structures that are created to solve the problem of climate change. Some of the ideas put forward are a large reflective dome placed on the poles to reflect sunlight away, thus cooling the poles are helping stop ice melt. Other ones have been to paint all the penguins white! There are a wide range of ideas but all of them have negative impacts. So we must decide if the negatives out way the positives.

      So far i am firmly on the non geoengineering side. I think we should take a more natural approach, but the debate will continue for many years to come!

    • Photo: James Pope

      James Pope answered on 3 Jul 2012:

      Hi littlemisstiger,

      The very first step to try to stop climate change is for us to start making big cuts to our fossil fuel useage, along the lines of a 25% cut by 2020 dropping to us being essentially carbon neutral by 2050, if we are to avoid warming of greater than 2°C by 2100, the point seen as being when ‘dangerous’ climate change will occur. Problems with this arise from the fact that, over the thousend years or so we are stuck with the level of warming we set ourselves at, is whether we can stop ice sheets from melting, 3 million years ago in the Pliocene, the world had much smaller ice sheets than today, with 25m of sea level rise back then, but only 3°C warmer than today, so over longer timescales what we are committed to by our emissions may not save the ice sheets.

      If we can’t make the changes to our emissions then the only alternative to just letting the warming happen is called Geoengineering. The idea is that fossil fuels trap more solar energy in, warming the planet, so if we reduce the solar energy coming in then we have less being trapped and climate won’t change. Some of these schemes suggest we can remove carbon dioxide from the atmosphere, but most of these would be very hard to achieve, so we are focussing our research on reflecting solar radiation. I studied my masters project on using sulphate chemicals and putting them in the high atmosphere, like after a large volcanic eruption. My flatmate did his PhD (completed about 3 weeks ago) on making certain types of clouds brighter by spraying sea salt into them. We test these ideas on a climate model and while they do reduce the changes to the climate from global warming, they can cause regional impacts such as damage to rainfall patterns. Some of these changes could be worse than the effects of the warming and so geoengineering maybe worse. Ultimately, we can’t test it for real without actually affecting our climate so it’s very hard to know what to do next. But oth my flatmate and I are against the idea of using geoengineering at the moment.

      It is a great question though, as sea ice melt and ice sheet melt will have massive feedbacks into the climate system and could amplify (increase) how bad the warming is from our emissions.