Climate change – and my reasons for being doubtful

Suffolk meteorologist James Dent outlines his reservations about some of popular views on the issue

New observations which cast some doubt on the causes of climate change – and the realisation that Government energy policies are proving economically crippling – mean that the climate change story continues to be high-profile.

My professional experience and scientific basis of my education has led me to approach the long-running topic of climate change in a balanced manner.

This means I am labelled a ‘sceptic’, an almost derogatory term in environmental circles. It appears impossible not to be categorised in an all-or-nothing way.

My views have led to accusations of being in the pay of oil companies, and in a recent live phone-in on The Warr-Zone I was asked if I recycled. I do: I also have solar water heating, a photo-voltaic generating system and do not drive a gas-guzzling vehicle. Apparently these preferences should preclude me from doubting orthodox viewpoints on climate change issues. I hope this article can explain some of the reasons for my reservations.


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The basic premise to the whole complex of climate policy and its fixation with ‘carbon’ is based on the assumption that carbon dioxide (CO2) is a ‘greenhouse gas’, and that its concentration in the atmosphere is directly linked to global temperature. Thus an increase in CO2 concentration has caused (will cause) a rise in atmospheric temperature, and vice-versa.

This concept is simplistic in the extreme. The heat balance of the atmosphere, between incoming radiation, absorption and loss of heat by the earth and water surface, reflection by clouds, etc., is highly complex, made even more complicated by the dynamic movement of water vapour around the world by its weather systems. Evidence over geological time suggests that the concentration of CO2 responds to temperature, not the other way round.

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The projections of climate change on global, regional and national scales, and in the national climate projections programme (UKCP09), are made by highly complex computer models. Although these models are very sophisticated in mathematical terms, they are only approximations of the reality of atmospheric behaviour, and are subject to approximation and inaccuracy.

Models operate on coarse scales for area and time-steps. Results are usually expressed for seasons and large areas, and are very difficult to focus on even relatively small area like East Anglia.

Climate change models are really only effective for modelling temperature, projections for wind and precipitation only being inferred indirectly. UKCP09 presents the model results both in a regional context, and in terms of probability, and also highlight the range of variability likely.

This should lead end users to be more circumspect about how climate change projections may be applied, but the Government and the media still put out yesterday’s “messages” of “hotter, drier summers, warmer, wetter winters and more extreme weather.”

As well as dire predictions for climate in the future, the media delights in attributing any extreme conditions, be they for a day, week, month or season, to climate change. Most climate scientists and professionals in related disciplines do not accept this claim.

The historic records of temperature, rainfall and river flow invariably contain examples of more extreme events in the past, so the future should not hold surprises. The basis of engineering design, a vital part of resilience and adaptation, depends on statistics gleaned from observations. Observations are also, of course, the foundation of models, which can only be as good as the data with which they are calibrated.

Ground-based observations (weather stations, river gauges) are now in decline world-wide; vast areas of the globe have few or no observation stations, and many of these areas, for example desert margins and tropical rainforests, are some of the most critical locations for climate and weather risk.

Remote sensing does not magically improve the situation. Much remote sensing, form example weather radar and satellites, depend on indirect measurement from radiation wavelength interference. These are highly complex relationships and need sophisticated calibration to retain reasonable accuracy.

Touching on extreme events, the table (severe rain storms) lists the 12 most severe rain storms since 1900, in chronological order.

The Boscastle event is only one of two extreme events since 1973, which does not suggest a dramatic change has taken place due to climate change. The contention that the predicted hot-dry summers and warm-wet winters are already upon us, can equally be demonstrated as untrue. Met Office data for East Anglia (see table East Anglia’s weather) show that the last time summers or winters fell into the extreme category was the mid-90s, and similarly extreme conditions had occurred in the early part of the last century.

Worldwide, climate change is given as the reason for many extremes and problems, especially floods and droughts. Frequently, the issue is really about impacts of events, rather than the nature of their cause. A simple example to illustrate this is flooding in Bangladesh. The monsoon floods are an annual event, and vary from year to year, but the media line is that floods are getting worse.

Far from increasing in recent years, the extent of flooding has decreased over the last four years, and the moving average levels are now almost identical to those at the beginning of the record. There are probably structural reasons for the increase in variability since the 1970s. The fact that over the period since 1954 the population of Bangladesh has increased from 50 million to 160 million (World Bank statistics), may have something to do with increasing impact of floods.

How and why does the climate change hype keep going? There is abundant peer-reviewed literature and research being reported that at least question the popular projections of climate change, if not completely destroying them. It is now recognised that the UN International Panel on Climate Change reports issued in 2007 are seriously flawed and biased.

Claims that the Himalayan glaciers will disappear in 25 years are now admitted to be totally erroneous, and much other material has been provided by pressure groups. The “drowning polar bears” story has also now been exposed as fabrication.

Over the last 20 years emissions have continued unabated. In this time CO2 concentration in the atmosphere has increased at an average of about 2ppm per year (British Isles measurement facility in Galway). There has not been a similar progressive increase in atmospheric temperature, either globally or locally.

It is generally recognised that 1998 was the hottest year with regard to global temperatures. From Met Office figures for East Anglia, average temperatures peaked around 2003 and have been declining since. This does not seem to me to be the sort of incontrovertible proof on which to establish complex and far-reaching legislation, nor produce quasi-religious fervour that vilifies unbelievers.

The politics of climate change are convoluted, to the point of being sinister. The idea of carbon credits and carbon trading, however well-intentioned, have turned into a global means of making money.

The carbon market is now worth $184billion. Recent evidence from Japanese satellite observations shows that CO2 emissions from developing countries are far in excess of those from economically developed areas. Natural phenomena such as volcanic eruptions, and emission of CO2 from rivers and the sea, dwarf the level of CO2 produced by human activities. CO2 accounts for 0.039% of the atmosphere, most of which is natural. The UK contributes 2% of the world’s CO2 emissions, and there is no observational proof that cutting CO2 emissions will directly result in a decrease in atmospheric temperature and other phenomena.

There is evidence that in several countries, Uganda and Honduras for example, people are being forcibly removed from land so that trees can be planted to compensate for “our” carbon footprint.

Perhaps the reality of other “combating climate change” measures will begin to strike home when the UK energy costs drive millions into fuel poverty and close businesses. Climate change and erratic weather have always happened, and the best way to cope is as we have always done, through resilience, preparedness and adaptation. Most of these measures are based on common sense, which cannot be said for the bizarre geo-engineering schemes which are being encouraged by Government funding.

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