My Lords, I congratulate the noble Baroness, Lady Sheehan, on securing this debate. Like her, I want to emphasise the importance of science and the IPCC. I studied physics at Cambridge, so I know that the basic science of global warming is rock solid—but many predictions about the likely consequences of higher temperatures are flimsier and claims of harms attributed to climate change sometimes lack any scientific basis.
First, you cannot prove a trend from a single event, however dramatic, or from a single year, however unusual. As an example, last year wildfires near some fashionable tourist resorts and smoke from Canadian wildfires blowing down to New York led to claims that this proved we were all going to roast. But NASA satellites have monitored wildfires for a couple of decades and I looked up what the NASA site said. It said that the area burned by fires had declined by 25% over the period that it had been monitoring it, and that on a typical day in August—it was August when I looked it up—there are 10,000 fires burning worldwide, so plenty to choose from if you want to be alarmist. Hurricanes and individual storms are dramatic, but there is no upward trend in hurricanes or in the damage they cause relative to the size of the world economy.
In the opposite direction, sea ice, which the noble Baroness, Lady Sheehan, mentioned is currently—this January—at the highest level for 23 years. But of course my point about a single event and a single year not being able to prove a trend applies just as much to that. Like her, I imagine that over time a warmer climate will lead to the melting of Arctic ice. But that is not the same as onshore ice—or rather, it will have the same effect on onshore ice. The noble Baroness quoted the IPCC but did not go on to say, as it says in paragraph 5.22 of its report on 1.5 degrees global warming, that this will take hundreds to thousands of years. I think that we can possibly deal with it over that period.
The best summary of what the IPCC says is in chart 12.2 in its most recent assessment review. It assesses what impact climate change has been having, whether it is out of line with variability in the past and what is expected to happen up until 2050 and the end of the century. It says, of course, that temperatures have been rising and are expected to go on rising. Extreme heat, as a result, has been rising and will go on rising. Mean precipitation has not yet risen out of line with normal variability but is expected to do so before 2050 and in the second half of the century. It will be more extreme in some areas and less extreme in others. However, the IPCC says that it has neither observed, and nor does it forecast, up to the end of the century, anything unusual in the way of river floods, landslides, droughts, wind speeds, storms, cyclones or fire weather. Despite the fact that it expects a continuing rise in sea level, it does not expect that to cause any appreciable or unusual coastal floods or erosion.
I think we ought to take into account what the IPCC says about these things. When I raised it before with the Minister’s colleague, his officials wrote back and said, “Oh, but that’s just in the science section of the IPCC report”. Well, I thought it was the science we were supposed to take seriously. But if we do not, previously I asked Ministers whether they knew of any IPCC-assessed reports that suggested that if we did nothing to stop global warming, it would lead to the extinction or elimination of the human race. They said there were none. So, let us not encourage exaggeration. I do not want to see global warming continue, because I am a Conservative and I do not like unnecessary change—but it is not going to lead to the elimination of the human race.
Let us look at the opening words of the economic chapter of the IPCC report:
“For most economic sectors, the impact of climate change will be small relative to the impacts of other drivers. Changes in population, age, income, technology, relative prices, lifestyle, regulation, governance, and many other aspects of socio-economic development will have an impact on the supply and demand of economic goods and services that is large relative to the impact of climate change”.
So I urge those who get alarmed about climate change to actually read the science. When they do, they will find it is a problem, but not the end of the world.