Martin Rees: 2010 Reith Lectures

Our Radio National is a touch behind, since these lectures have just begun here in Australia. I have heard the first of them. Lord Martin Rees, the Astronomer Royal, is President of the Royal Society.

In the first of this year’s Reith Lectures, Lord Martin Rees explores the challenges facing science in the 21st century. We are increasingly turning to government and the media to explain the risks we face. But in the wake of public confusion over issues like climate change, the swine ‘flu vaccine and, more recently, Iceland’s volcanic ash cloud, Martin Rees calls on scientists to come forward and play a greater role in helping us understand the science that affects us all.

In the second lecture, not yet heard in Australia but available from the BBC, Lord Rees becomes more specific about a range of issues, including Climate Change.

…Another firm prediction about the post-2050 world is that, as well as being more crowded, it’ll be warmer. By how much is a matter of continuing research. The greater the warming, the greater the risk of tipping, for instance, gradual melting of Greenland’s ice cap or the release from the Tundra of methane, which would lead to further warming. And that’s the motive for attempts to reduce global consumption of fossil fuels.

The declared political goal has been to halve global carbon dioxide emissions by the year 2050. This corresponds to a ration of 2 tonnes of carbon dioxide per year, each person on the planet. For comparison, the current US level is 20 tonnes per person per year; European figures about 10; the Chinese level’s already 1.5; and the Indian is 1.5. In cutting these emissions, the richer countries must take the lead without stifling economic growth in the developing world where emissions in the short-term are bound to rise.

Success in halving global carbon emissions would be a momentous achievement – one where all nations acted together in the interests of a future beyond the normal political horizon. The meagre progress in Copenhagen last December didn’t instil optimism. On the other hand – odd though this may sound – the political response to the financial crisis may offer encouragement. Who would have thought two years ago that the financial system would have been so transformed that big banks were nationalised? Likewise we need coordinated, outside-the-box action to avoid serious risk of a long-term energy crisis.

The world spends more than 5 trillion dollars a year on energy and its infrastructure. There’s a glaring contrast here with health and medicine where worldwide R&D expenditures are much, much higher. The clean energy challenge deserves a priority and commitment akin to the Manhattan Project or the Apollo moon landing.

It’s sometimes said fatalistically that the UK’s stance on all this is of marginal import because our carbon emissions are only 1 or 2 percent of the problem. But we have leverage in two respects. First politically. We’ve earned international influence because of the UK government’s leadership ever since the Gleneagles G8 Summit, and because we’ve already enshrined in our Climate Change Act a commitment to cut our own emissions by 80 percent over the next 40 years. Second, we have the expertise to spearhead some of the technologies needed for a low carbon economy. We need to keep our lights on to ensure energy security for ourselves, but beyond that imperative it’s in our interest not to fall behind the Chinese in developing clean energy technologies that the world will need.

In wave and tidal energy, for instance, the UK could lead. We have the geography – capes round our coast with fast-flowing tidal currents – and we have marine technology from North Sea oil and gas. And since I’m speaking in Cardiff, I should highlight the Severn barrage scheme as well.

What about biofuels? There’s been ambivalence because they compete for land use for food growing and forests, but in the long-run GM techniques may lead to novel developments: bugs that break down cellulose or marine algae that convert solar energy directly into fuel.

Another need is for improved energy storage. In the US Steve Chu, the Nobel Prize-winning physicist whom President Obama appointed as Energy Secretary, has given priority to improving batteries – for electric cars and to complement unsteady power sources such as sun and wind and tides.

What’s the role of nuclear power? I’d myself favour the UK having a replacement generation of nuclear power stations – and boosted R&D into ‘fourth generation’ reactors and into nuclear fusion. But one can’t be relaxed about a worldwide expansion of nuclear power unless internationally regulated fuel banks are established to provide enriched uranium and remove and store the waste. Otherwise there’s too much risk of weapon proliferation.

I think an attractive long-term option for Europe is solar energy: huge collectors – most maybe in North Africa – generating power that’s distributed via a continent-wide smart grid. Achieving this would require vision, commitment and public-private investment on the same scale as the building of Europe’s railways in the 19th century.

Some pessimists argue that the transition to a low carbon economy won’t happen fast enough, and that the international community should, as a fallback, contemplate a ‘plan b’ – being fatalistic about the rise in carbon dioxide, but combating the warming it induces by, for instance, putting reflecting aerosols in the upper atmosphere or even vast sunshades in space.

The political problems of such geo-engineering may be overwhelming: not all nations would want to turn down the thermostat equally, and there could be unintended side effects. An alternative geo-engineering approach would be direct extraction of carbon from the atmosphere. This approach would be more acceptable politically. But it seems to me right at least to study geo-engineering, to clarify which options make sense and which don’t; to explore the governance issues they raise and perhaps damp down undue optimism about a technical quick-fix of our climate.

Energy security, food supplies and climate change are the prime long-term threats without enemies that confront us – all aggravated by rising populations…

In the first lecture Lord Rees had shown an awareness of the limits of certainty that escapes most climate change denialists who are usually only too certain.

There’s no denying where science has recently had the most contentious policy impact, and where the stakes are highest: climate change.

It will feature, along with other global threats, in my second lecture, but I’ll venture some comments today too. As regards the science, there is, in my inexpert view, one decisive measurement: the amount of carbon dioxide in the atmosphere is higher than it’s been for a million years, and is rising, mainly because of the burning of fossil fuels. This finding isn’t controversial. And straightforward chemistry tells us that carbon dioxide is a so called ‘greenhouse gas’: it acts like a blanket, preventing some of the heat radiated by the Earth from escaping freely into space. So the measured carbon dioxide build-up in the atmosphere will trigger a long-term warming, superimposed on all the other complicated effects that make climate fluctuate.

The predicted rate of warming, however, is uncertain – depending on the poorly-understood ‘feedback ‘ from water vapour and clouds, which themselves affect the blanketing. Nevertheless, even the existing uncertain science convinces me that the threat of disruptive climate change is serious enough to justify its priority on the agenda of this country and others.

This confidence may surprise anyone who has dipped into all that’s been written on the subject. Any trawl of the internet reveals diverse and contradictory claims. So how do you make up your mind? I’d suggest the following analogy.

Suppose you seek medical guidance. Googling any ailment reveals a bewildering range of purported remedies. But if your own health were at stake, you wouldn’t attach equal weight to everything in the blogosphere: you’d entrust your diagnosis to someone with manifest medical credentials. Likewise, we get a clearer ‘steer’ on climate by attaching more weight to those with a serious record in the subject.

There’s an excellent TV series by Rees which you may commence here: