Global warming clock is ticking

The UK is in denial about its real carbon emissions, suggests a report from the Stockholm Environment Institute. The academics conclude that if “outsourced” emissions produced in countries like China on goods which are imported into the UK are included in our total carbon footprint, this country’s total greenhouse gas emissions are 49% higher than currently reported. So we should think twice when blaming the Chinese for emitting the CO2 that is required in the manufacture of our fridges and televisions.

The report illustrates once again – as if we had forgotten – that global warming is an, er, global issue. A tonne of CO2 is a tonne of CO2, wherever it is emitted. How you do the counting is more a matter of politics than mathematics. A much greater concern is that all the politics is in danger of obscuring the increasingly drastic nature of the climate change threat. According to Andrew Simms of the New Economics Foundation, the world has only got 100 months left if we are to have a reasonably high chance of staving off runaway global warming.

This is a pretty dramatic claim, and the associated onehundredmonths.org website has an equally dramatic ticking clock counting down until runaway warming begins. “When the clock stops ticking,” it states ominously, “we’ll be beyond the climate’s tipping point, the point of no return.” Yikes. So how valid is this claim? Luckily, NEF’s website provides a 100 Months technical note (pdf)explaining the calculations behind the new campaign. The first thing I noticed is that there isn’t any new modelling work underlying the claim: it is based on existing science, in particular on an analysis by a researcher called Malte Meinshausen which was published in 2006.

Meinshausen was the first scientist to quantify with percentage figures the probability of exceeding certain climatic thresholds: in his 2006 paper he concluded that only by stabilising greenhouse gas concentrations in the atmosphere at 400 part per million (ppm) would it be “likely” (defined as 66-90% chance) that the world would stay below an eventual warming of two degrees. The NEF analysis has performed a fairly simple calculation, simply counting the time left before this 400ppm level is reached. The deadline, it turns out, is 1 December 2016.

There are several complicating factors, however. The 400ppm figure in question is not for CO2 only, but for a basket of atmosphere-altering gases – some of which have a positive “forcing” effect (like CO2 itself) whereas others have a negative (cooling) effect, like sulphate aerosols released by industry. Add the sum of these forcings together and you can arrive at a “CO2-equivalence” figure, which is the one that both NEF and Meinshausen use. The timescales need to be borne in mind, however: CO2 resides in the atmosphere for a century on average, whereas aerosols are washed out by rain in just a week or so.

There are other caveats too. Meinshausen is not saying that two degrees of warming will be reached with certainty when we cross the 400ppm threshold, but that the risk of seeing two degrees increases steadily thereafter. (Even at 400ppm there is still a risk of overshooting 2C, of somewhere between 2% and 57%.) At 450ppm the risk of crossing the 2C line rises to between 26 and 78%, whereas at 550ppm the risk of overshooting is between 68 and 99%. Indeed, for 550ppm the risk of overshooting even 3C ranges from 21% to 69%.

So what do all these numbers mean? Reading the small print, sceptics might complain about the false precision implied by the 100 months clock, which seems to suggest that the minute, indeed the second, we pass 400ppm we are certain to see two degrees of warming. The truth is that no one knows where any of the relevant climatic tipping points – from the disappearance of the Arctic ice cap to the release of methane from melting permafrost – actually lie. There are uncertainties regarding both what level of carbon emissions equals what temperature rise, and what temperature rise equals which climatic impacts. All we can say with near-certainty is that the warmer it gets, the further into dangerous territory we stray.

And again, there is the question of timescales. Meinshausen’s two degrees calculations referred to two degrees of warming, not the minute the 400ppm line is crossed in December 2016, but when the atmosphere reaches “equilibrium” – in other words when all the warming processes have had a chance to feed through the system. Like a boiling kettle, the planet has a substantial thermal timelag – it takes a long time for ice sheets to rebalance themselves and for warmer waters to penetrate to the bottom of the deepest oceans. So even at this “tipping point” we still wouldn’t see the expected two degrees of warming until the end of the century at least, if today’s climate models are to be believed.

Reassuring, perhaps – but no cause for complacency. The earth’s thermal timelag also means that today’s emissions will keep on causing warming for decades to come, and that decisions made today on emissions cuts are essential if we are to rebalance the climate in the second half of the century.

The great danger of climate change is that it is a long-term systemic process. Self-evidently urgent threats – like wars or economic collapse – are easy to put at the top of our list of priorities. But climate change is a very slow process (note the current sceptic line of decrying the lack of year-on-year warming as hoped-for proof that it’s all been a big mistake), and one where cause and effect (CO2=climate disasters) are not at all obvious at any intuitive level, hence the continuing predominance of wishful thinking, conspiracy-theorising and outright denial. Climate change clearly does not engage our natural psychological self-defence mechanisms.

This is the value of the 100 months campaign, which injects a sense of urgency into what is in reality a very slow process of cooking ourselves. We need to frame this issue as an urgent one to generate anything like an appropriate response, and indeed NEF explicitly uses the wartime analogy. But the drawback is also clear: in January 2017, after the deadline passes, people might either become fatalistic (”we’ve passed the tipping point, so let’s give up”) or might turn increasingly sceptical (”things don’t look any different – I thought you said the world was going to end?”). In reality, this is a matter of risk analysis: how much risk of destroying our planetary habitat are we prepared to bear in order to keep on burning fossil fuels? Quite a lot, it would seem.

Source - The Guardian

Does mankind have the foresight to save itself?

Sometimes we need to think the unthinkable, particularly when dealing with a problem as dangerous as climate change - there is no room for dogma when considering the future habitability of our planet.

It was in this spirit that I and a panel of other specialists in climate, economics and policy-making met under the aegis of the Stockholm Network thinktank to map out future scenarios for how international policy might evolve - and what the eventual impact might be on the earth’s climate. We came up with three alternative visions of the future, and asked experts at the Met Office Hadley Centre to run them through its climate models to give each a projected temperature rise. The results were both surprising, and profoundly disturbing.

We gave each scenario a name. The most pessimistic was labelled “agree and ignore” - a world where governments meet to make commitments on climate change, but then backtrack or fail to comply with them. Sound familiar? It should: this scenario most closely resembles the past 10 years, and it projects emissions on an upward trend until 2045. A more optimistic scenario was termed “Kyoto plus”: here governments make a strong agreement in Copenhagen in 2009, binding industrialised countries into a new round of Kyoto-style targets, with developing countries joining successively as they achieve “first world” status. This scenario represents the best outcome that can plausibly result from the current process - but ominously, it still sees emissions rising until 2030.

The third scenario - called “step change” - is worth a closer look. Here we envisaged massive climate disasters around the world in 2010 and 2011 causing a sudden increase in the sense of urgency surrounding global warming. Energised, world leaders ditch Kyoto, abandoning efforts to regulate emissions at a national level. Instead, they focus on the companies that produce fossil fuels in the first place - from oil and gas wells and coal mines - with the UN setting a global “upstream” production cap and auctioning tradable permits to carbon producers. Instead of all the complexity of regulating squabbling nations and billions of people, the price mechanism does the work: companies simply pass on their increased costs to consumers, and demand for carbon-intensive products begins to fall. The auctioning of permits raises trillions of dollars to be spent smoothing the transition to a low-carbon economy and offsetting the impact of price rises on the poor. A clear long-term framework puts a price on carbon, giving business a strong incentive to shift investment into renewable energy and low-carbon manufacturing. Most importantly, a strong carbon cap means that global emissions peak as early as 2017.

This “upstream cap” approach is not a new idea, and our approach draws in particular on a forthcoming book by the environmental writer Oliver Tickell. However, conventional wisdom from governments and environmental groups alike insists that “Kyoto is the only game in town”, and that proposing any alternative is dangerous heresy.

But let’s look at the modelled temperature increases associated with each scenario. “Agree and ignore” sees temperatures rise by 4.85C by 2100 (with a 90% probability); for “Kyoto plus”, it’s 3.31C; and “step change” 2.89C. This is the depressing bit: no politically plausible scenario we could envisage will now keep the world below the danger threshold of two degrees, the official target of both the EU and UK. This means that all scenarios see the total disappearance of Arctic sea ice; spreading deserts and water stress in the sub-tropics; extreme weather and floods; and melting glaciers in the Andes and Himalayas. Hence the need to focus far more on adaptation: these are impacts that humanity is going to have to deal with whatever now happens at the policy level.

But the other great lesson is that sticking with current policy is actually a very risky option, rather than a safe bet. Betting on Kyoto could mean triggering the collapse of the West Antarctic ice sheet and crossing thresholds that involve massive methane release from melting Siberian permafrost. If current policy continues to fail - along the lines of the “agree and ignore” scenario - then 50% to 80% of all species on earth could be driven to extinction by the magnitude and rapidity of warming, and much of the planet’s surface left uninhabitable to humans. Billions, not millions, of people would be displaced.

So which way will it go? Ultimately the difference between the scenarios is one of political will: the question now is whether humanity can summon up the courage and foresight to save itself, or whether business as usual - on climate policy as much as economics - will condemn us all to climatic oblivion.

Source - The Guardian