Jun 2nd 2010
Loading ...Climate change facts, uncertainties and actions
On Tuesday 26 May 2010, Lord May of Oxford gave a public lecture at the UTS School of the Built Environment. He outlined the science behind climate change, the UK response, and the international status quo after Copenhagen.
In the 150 years since Darwin’s Origin of Species, the world’s population has grown from less than one billion to almost seven billion people. The amount of energy required to support the daily activity of the average person – for food, transport, housing and so on – has also increased sevenfold.
The two combined mean that humanity’s total energy ‘footprint’ has increased more than fifty-fold – arguably beyond the limit of sustainability for the planet. Although there are variations between countries, the fact is that each year we burn about a million years’ worth of fossil fuel deposits, and it is beginning to affect the climate.
What we know (and don’t know) about the way we are changing the climate
The climate has undergone terrific changes over the five billion year history of planet earth – from snowball to tropical oven. Ice ages have come and gone even in the last 200,000 years.
But during the last 10,000 years (roughly since humanity began farming, built the first cities and started to increase in numbers), global temperature patterns have been relatively stable. There has been an atmospheric greenhouse gas (GHG) level of around 280 parts per million during this time, and scientists agree that this greenhouse gas ‘blanket’ is essential to maintain the temperature of the atmosphere.
Greenhouse gas levels in the atmosphere have increased sharply since the industrial revolution, accelerating through the last century to around 387-88ppm today – with no sign of slowing.
When concerns began about rising greenhouse gas levels, there was great uncertainty about the consequences. But as computing power has increased, we have been better able to model the effects of burning fossil fuels.
On the scale of tens of thousands of years we could expect global temperature swings due to factors other than greenhouse gases. Models suggest that, without fossil fuels, we might have seen the arctic cooling slightly in the next thousand years. However, we have seen it rise 0.7 degrees in the last century. By today, you cannot explain what we are seeing without recognising the effect of the thickening of the blanket.
Climate change sceptics are like people who say they don’t believe in tides because you can’t say when the next wave is coming. You have to distinguish sustained long-term trends from daily and seasonal fluctuations.
At the G8 summit in 2005, world leaders acknowledged three things: climate change is real; it is largely caused by us; and it is serious.
UK Legislation and consequences
In 2006, the Nicholas Stern Review looked at the effects of climate change on the global economy. The Review estimated the costs of stabilising GHG levels at 500-550ppm would be between 5% cost (or perhaps 2% gain) of global GDP.
By contrast, the costs of doing nothing would be 5-20% of global GDP (on average). There would be some winners in climate change, but the losers would be primarily equatorial places – already the poorer places in the world. The thinking was that if we can keep temperature increase to less than two degrees, then the worst consequences can be avoided.
The British response was a 2007 climate change bill calling for:
- legally binding targets;
- a committee to oversee those targets; and
- a framework for fiscal instruments to help.
In December 2008, the Committee on Climate Change (theccc.org.uk) produced its first report, calling for a global emissions reduction target of 50%. In order to stabilise atmospheric greenhouse gas levels, a global average of 2.5 tonnes per capita would be necessary.
To reach the 2.5 tonne average, the UK would have to reduce its present per capita emissions by 80% by 2050, which would still allow developing countries like India and China (currently both well under 2.5 tonnes per capita) to keep increasing.
The interim target is 34% by 2020, but with the desired target of 42% if a global deal is achieved.
The Stern Report acknowledged that if we do this and no one else does, we still inherit others’ messes. However, decisive, early action remains a good economic idea, providing energy security, water security and efficiencies that other countries will not have.
To date, the UK is one of the few countries to have actually reduced greenhouse gas emissions on 1990 levels, but there’s a long way to go.
Copenhagen and the Financial Crisis: good news and bad news
The bad news out of Copenhagen was that there was no ‘Kyoto 2’ agreement. However, there was some consensus:
- Climate change is real
- Global average temperature increases should be kept to 2°
- The science demands deep cuts in global emissions
- It is more efficient to do things early than late
- We need a tough set of targets
Leaders agreed that, to reach a global average, developed countries must move down to it, while developing can move up. Developing countries agreed to commit to targets, self-measured, but reported, and developed countries commited to providing resources and technology to help them achieve their targets.
During the Financial Crisis, many economic stimulus packages had green measures. There have been hiccups – a recent Utah bill in the US that said that there is no such thing as climate change, for example – but most countries are acknowledging the problem, and making gestures towards doing something about it.
The UK is one of the only places which has managed to reduce its carbon emissions in the last fifteen years. In all, what is important is how soon – earlier actions will have disproportionately large effects.
Climate change is real, and has serious implications for biological diversity, water scarcity, food security, hunger, coastal risk, and crop decline. Although we don’t yet know all the consequences, we do know that equatorial and developing countries will bear the brunt.
The hard sciences are rigorous. They are relatively easy. In some ways, the most important sciences are the social sciences that ask ‘how do you motivate people to do something?’
Lord May’s lecture was jointly presented by the UTS School of the Built Environment, Faculty of Design, Architecture and Building, and the Australian Institute of Building, with support from the APCCRPR and BEDM.
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