How about something that has nothing to do with the election?
Scourge of the Left and “Britain’s most toutspoken conservative” Norman Tebbit started a blog earlier this year to much cheer and chagrin.
Earlier this year Lord Tebbit provoked ire from the left when he pondered aloud on why Cameron chose the “trivialities of dress sense or political asylum for African homosexuals” over dealing with the deficit or the EU. On the other hand, Tim Montgomerie was more pleased with his increased visibility.
Last week he turned his attention to Climate Change. He surmised “in short, I am unconvinced by man-made global warming but not dogmatically sure that it is all nonsense, a racket or a conspiracy.”
However, Lord Tebbit is clear that he is not beyond convincing otherwise. In his own disparaging way he implores climate change sceptics to not be “dogmatic about climate change – unlike the warmists.”
In a succinct passage in the middle of his post he explains why he finds it difficult to dismiss the idea that humans are causing climate change.
I do not think it impossible that to burn in the space of a couple of centuries or so stocks of hydrocarbons which took tens if not hundreds of millions of years to lay down, and to release the carbon back into the atmosphere as carbon dioxide, may have some measurable effects upon our environment.
Luckily for us Lord Tebbit also explains why he is unsure whether this effect is “huge, large, small or insignificant” and this gives us an opportunity to explain why the effect is likely to be, with luck, merely large but quite possibly huge for life on earth.
There are a number of reservations which he explains temper any enthusiasm he has for the theory of man made climate change.
- As is commonly accepted he explains that the climate has changed before. For example, he explains that “we know that within comparatively recent times wheat was grown in Greenland.” Likewise he discusses the cultivation of vines as far north as Scotland [1] under Roman occupation.
- Lord Tebbit is also concerned that the scale of mankind’s emissions are small compared with “the variability of the sun to meteor impacts, or great volcanic eruptions.”
- In particular, the effects of the sun are likely to be larger than the effects of man.
- On top of these empirical concerns Tebbit is also worried on the fallibility of all too human scientists.
However, when it comes to past climate change, the observed data should actually convince us of the dangers of our carbon emissions rather than inoculate us against concern about them.
Data from past climates show us that the the earth is sensitive to energy imbalances such as those produced by the introduction of carbon dioxide into the atmosphere. The extra energy put into the system by the carbon we emit is reflected in higher temperatures.
And of course, while it is true that wheat was once cultivated in Greenland the Greenland ice sheet itself is at least 400,000 years old. Rather than be a source of solace, its past resilience and recent precipitous loss in mass should concern us all the more.
The changes in past climates have been the result of various natural forcings, things which effect the climate. For example the orbit of the earth is not completely circular and we can pass closer to the sun. Similarly our axis can tilt leading to more sunlight hitting certain parts of the earth altering the balance in the climate system. Atmospheric carbon dioxide represents another forcing.
Energy reaches us from the sun so an increase in solar activity can have significant effect on our climate. In fact this may be what allowed an agrarian polity to survive on Greenland albeit briefly. However, contrary to Lord Tebbit’s instincts the sun is not causing our current warming.
Below is a graph that illustrates that the sun simply is not causing the current warming trend which has seen “winters… become notably warmer” in Lord Tebbit’s lifetime.
As you can see the significant warming we have recorded since 1960 has not been caused by increase solar irradiance. In some ways I take an awkward pride in the awesome power of man compared to the sun, which is, remember, a star, and something which is creating out of sheer heat and pressure most of the elements which are the building blocks of life and our planet.
Of course Lord Tebbit is not just concerned about solar activity. He is correct that Volcanoes and other natural processes put carbon dioxide into the atmosphere but I think he will be surprised by the degree to which human emissions outstrip those emitted by volcanoes. The below graph illustrates the small effect volcanic eruptions have on our climate.
One matter on which Lord Tebbit and I differ on a more philosophical level is on the certainty with which we should treat these scientific findings now that we have established that the current evidence strongly suggests that mankind is causing climate change.
Lord Tebbit argues that he has “every respect for scientists, but they are human, they make mistakes, they are prone to follow fashions in ideas and they are reluctant to admit error.”
I cannot answer on behalf of scientists as I do not number among them, however 255 members of the U.S. National Academy of Sciences may have serendipitously addressed this point in a recent letter. I hope you will permit me a somewhat lengthy extract:
There is always some uncertainty associated with scientific conclusions; science never absolutely proves anything. When someone says that society should wait until scientists are absolutely certain before taking any action, it is the same as saying society should never take action. For a problem as potentially catastrophic as climate change, taking no action poses a dangerous risk for our planet…
… The Intergovernmental Panel on Climate Change (IPCC) and other scientific assessments of climate change, which involve thousands of scientists producing massive and comprehensive reports, have, quite expectedly and normally, made some mistakes. When errors are pointed out, they are corrected. But there is nothing remotely identified in the recent events that changes the fundamental conclusions about climate change:
- The planet is warming due to increased concentrations of heat-trapping gases in our atmosphere. A snowy winter in Washington does not alter this fact.
- Most of the increase in the concentration of these gases over the last century is due to human activities, especially the burning of fossil fuels and deforestation.
- Natural causes always play a role in changing Earth’s climate, but are now being overwhelmed by human-induced changes.
- Warming the planet will cause many other climatic patterns to change at speeds unprecedented in modern times, including increasing rates of sea-level rise and alterations in the hydrologic cycle. Rising concentrations of carbon dioxide are making the oceans more acidic.
- The combination of these complex climate changes threatens coastal communities and cities, our food and water supplies, marine and freshwater ecosystems, forests, high mountain environments, and far more.
Much more can be, and has been, said by the world’s scientific societies, national academies, and individuals, but these conclusions should be enough to indicate why scientists are concerned about what future generations will face from business-as-usual practices. We urge our policy-makers and the public to move forward immediately to address the causes of climate change, including the un restrained burning of fossil fuels.
There is a lot of evidence out there which is easily accessible that resolve many of the reservations he expresses with regard to the likelihood of mankind causing climate change. I do hope that Lord Tebbit reads this post and reconsiders his opinion on the subject.
Reaching across the aisle on matters as important as this is important and Lord Tebbit can do fifty fold what I can do to convince those to the right of centre still doubtful that we are changing the climate.
[1] Actually, there are two vineyards currently in operation in Scotland today and the south east of England is quietly cultivating a reputation for sparkling wines. On another wine related note, makers and drinkers of German wine – a country on the edge of where you can grow grapes – will have noticed that a country which once had 2 or 3 good vintages a decade is now consistently producing great wines thanks to the slightly warming we have seen. I love German wine so AGW offers quite the moral quandary to me.
What you've said