Gibson-Smith on our Ice Age
- <<Climate change is a fascinating subject. At stake are some huge
issues that really matter, so it is a subject that we should be
debating in a deep and thoughtful fashion. As a scientist at my core,
though, I feel that the quality of the public debate has been awful.
It has been characterised by exaggerations, extreme assertions by
people with no understanding of the science, and character
assassinations of those who question the orthodoxy.
Against this backdrop, I risk being branded a heretic for sharing my
views. But I do so as someone with an above average commitment to the
environment and understanding of the issues at hand; as a practising
Earth scientist for 20 years, with a PhD in Earth chemistry; as a
former member of the Sustainability Commission; and having sat on a
number of business forums on the environment.
To begin to understand climate change, it needs to be emphasised that
we are actually in the middle of an ice age. We are in a warm phase of
that ice age, but we are definitely in an ice age, and what is clear
is that we can expect to go back towards a period of deep cooling
again, possibly within the next 1,000 years. Indeed, between the 1950s
and 1970s, when the planet last experienced a period of cooling,
scientists were worried that we were moving back into the next major
ice pulse. When this cooling does happen, the northern half of the
Northern hemisphere may become uninhabitable.
One of the possible reasons we are in this ice age, is that carbon
dioxide concentrations in the atmosphere appear to be at their lowest
levels for nearly 50 million years. During the last ice pulse that
culminated 20,000 years ago, when Britain was covered in ice sheets
miles thick, carbon dioxide concentrations were as low as 190 parts
per million, which is equivalent to 0.019 per cent of the atmosphere.
They have now risen to around 379 parts per million, but 50 million
years ago they were at 1,400 per million. The probable reason for this
relatively low level of carbon dioxide is that volcanic activity has
gradually declined over the past 50 million years, so the only source
of new CO2 in the atmosphere has been declining while other processes,
such as weathering and photosynthesis, have continued to strip carbon
out of the atmosphere and bury it in the earth.
It is clear that carbon dioxide is one factor that influences climate.
Without the greenhouse effect it creates, the planet would be a
permanent ice ball and there would be no life as we know it.
Historically, rises in CO2 seem to have followed temperature
increases, but human activities are now introducing something new that
hasn't happened before.
Oddly, however, although we are raising the carbon dioxide levels in a
linear fashion, the temperature is not behaving in the way it should
if there was a simple linkage. Clearly, there are things going on
which we do not yet understand. This is true of climate change as a
whole. The science is complex and can only begin to be understood by
blending astronomy, geology, biology, oceanography and meteorology.
There are many uncertainties and disagreements about how these
disciplines contribute and interact with each other. There is still
great uncertainty over the role of the Sun, how the Earth's orbit
affects climate, the way the oceans take up carbon dioxide and the
role biology has to play in the planet's climate.
This all makes it difficult to predict what is going to happen, and it
reduces the credibility of those who suggest that the science is
certain. In fact, the predictions give a wide range of possible
outcomes and at the moment the temperature changes are tracking the
low end of the forecasts. The current trend could take us back to
European temperatures of 1,000 years ago within 100 years.
When it comes to building our economic policy responses, which is
where my interest as chairman of the London Stock Exchange comes in,
we need to accept the level of uncertainty that exists. This may make
the task more challenging, but the alternative, the way we are going
about it at the moment, is very likely to produce some bad answers.
Simplistic responses are likely to be damaging. Take 4x4s, for
instance. While I can't see the point of them in towns, taxing them in
terms of climate is meaningless, except on a symbolic level. Aviation
has also been unfairly targeted. It makes up a tiny part of the total
contribution to emissions, around 2 per cent but, like taxes on
tobacco and alcohol, it has been carefully targeted not to change
behaviour while raising large amounts of tax revenue.
What would make sense would be long-term tax and economic policies
aimed at raising the manufacturing efficiency of our economy, and so
improving our competitiveness while limiting environmental damage. We
need long-term reductions in the amount of energy required to produce
each additional £1 of GDP, in the efficiency of buildings,
transportation and power generation.
Ultimately, though, we have to accept that the UK is a minnow in
climate terms. We are responsible for less than 2 per cent of global
emissions, so even if we were to become perfect, our contribution
would be negligible. There is no point in damaging our competitiveness
and reducing our GDP if the planet will never notice.
What we should be doing is focusing on a related issue over which
there is greater certainty: resource depletion. Future development
worldwide is likely to be increasingly dominated by competition for
resources and raw materials, significantly raising costs. This country
really ought to be looking for international collaboration in tackling
the problems that will arise. Global challenges require global
solutions. We need to bring the United States, the EU, China, India,
Russia, Brazil, and the developing world into the equation because
there are no solutions unless we do.
This, of course, is a goal that has remained unachievable despite
years of trying. So, there needs to be a steady long-term policy in
the UK that aims to enrol the rest of the global community. As part of
the European Union, we form a large enough block to begin to make a
You can read this at: