Nature will decide Earth’s fate … climate change sceptics are waryDecember 10, 2009
* By Professor Bob Carter
* From: The Daily Telegraph
* December 09, 2009 11:46AM
As the core samples from deep underground pass through the logging sensor before me, the rhythmic pattern of ancient climate change is clearly displayed. Friendly, brown sands for the warm interglacial periods and hostile, sterile grey clays for the cold glaciations. And for more than 90 per cent of recent geological time the Earth has been colder than today.
We modern humans are lucky to live towards the end of the most recent of the intermittent but welcome warm interludes. It is a 10,000 year-long period called the Holocene, during which our civilizations have evolved and flourished.
The cores tell the story that this period is only a short interlude during a long-term decline in global temperature – they also warn of the imminence of the next glacial episode in a series stretching back more than 2 million years.
Together with 50 other scientists and technicians, I am aboard the drilling ship Joides Resolution. JR, as it is affectionately known, is the workhorse of the Ocean Drilling Program, an international program that is to environmental science what NASA is to space science.
JR’s drilling crew can retrieve cores up to 1km or more below the seabed and we are drilling today about 80km east of South Island in New Zealand. The ancient muds and sands that make up the sediment layers we pass through are the most important record of ancient climate that scientists possess. And they tell the tale that climate always changes.
Some core alterations are ruled by changes in the Earth’s orbit at periods of 20,000, 40,000 and 100,000 years, others by fluctuations in solar output and others display oceanographic and climate shifts caused by . . . we know not what.
Climate, it seems, changes ceaselessly: sometimes cooling, sometimes warming, oft-times for reasons we do not fully understand.
Similar cores through polar ice reveal, contrary to received wisdom, that past temperature changes were followed – not preceded but followed – by changes in the atmospheric content of carbon dioxide.
Yet the public has been misinformed to believe that increasing human carbon dioxide emissions will cause runaway warming; it is surely a strange cause of climate change that postdates its supposed effect?
The now numerous special interest groups who continue to lobby for unnecessary and economically harmful carbon dioxide taxation need to appreciate that nature, not the world’s governments, will determine future climate. Second, that there is no scientific evidence that warmings greater than the much-talked about 2C will cause environmental catastrophe; rather, this number is one plucked out of the air for reasons of political targetry and control. And, third, that to limit atmospheric carbon dioxide to 450ppm, also a widely touted figure, makes no sense, because past carbon dioxide levels attained more than 10 times this without known adverse environmental effects, while greening the planet.
Politically popular though it may be, the belief that atmospheric carbon dioxide is the primary driver of average planetary temperature is junk science. For instance, Earth experienced an ice age about 450 million years ago at a time when atmospheric carbon dioxide levels are estimated to have been 15 times the pre-industrial level.
It is simply science fiction to believe that 450ppm of atmospheric carbon dioxide and 2C of warming are magic numbers that somehow mark a “tipping point”in Earth’s climate system. Rather, they are politically contrived targets, erected for the purpose of stampeding scientifically innocent citizens into a gaping corral of carbon dioxide taxation.
The simplest explanation for the mild warming that occurred in the late 20th century is that it was part of Earth’s ever-changing pattern of natural climate change and the job of scientists is to seek evidence to test that interpretation. They have and literally thousands of scientific papers to date have described climate evidence that is consistent with natural change.
Despite all the efforts of the Intergovernmental Panel on Climate Change (IPCC), and the expenditure of about $100 billion of research money since 1990, no scientific paper exists that demonstrates that the late 20th century warming, or the past 10 years of cooling for that matter, fall outside the rates and magnitudes of past (geological) climate change.
Melting glaciers (but, in some places, advancing), rising sea levels (but, in some places, falling), increasing numbers of storms (actually, currently at a 30-year low), increasing numbers of polar bears and changes in migratory patterns of birds may very well all have happened or be happening. But these facts say nothing about a human causality for such changes.
It is not for the independent climate scientists (the so-called “climate sceptics”) to disprove that dangerous human-caused warming is happening. Rather, it is for the alarmist scientists of the IPCC and CSIRO to show that the simple idea of natural climate change can be invalidated. This they have failed to do.
Professor Bob Carter, currently aboard a research ship near New Zealand, is a research professor at Queensland’s James Cook University – where he was Professor and Head of School of Earth Sciences between 1981 and 1999 – and the University of Adelaide