Climate change is the greatest global challenge, and science, engineering and technology have key roles to play in helping the world both to adapt to the change and to mitigate it.
That was the key message from Prof Sir David King, the UK's chief scientific adviser, to a large audience at the University of Limerick last week. He was speaking on the imperatives for action provided by the science of climate change.
Sir David was giving the first Academy Times discourse to be presented at UL. The meeting was chaired by Prof Jim Slevin, President of the Royal Irish Academy, and was organised by the Academy and The Irish Times.
While remaining as 1920 Professor of Chemistry at Cambridge University, Sir David was appointed as the UK government's chief scientific adviser and head of the office of science and technology in 2000. He led the initiative that last year produced the Foresight Future Flooding report, which assessed the risks to the UK from flooding 30 to 100 years ahead, as predicted by scientific models. The study of climate change is a mature science, and scientists are agreed that significant change is under way, Sir David said.
In 1827, Fourier understood the greenhouse effect and formulated it in terms of energy in from the sun minus energy out. Later, Tyndall made the first measurements of how the atmosphere absorbs energy. And 1903 Chemistry Nobel prize-winner Arrhenius was the first to assess the importance of the effects of burning fossil fuels.
"The oil reserves are a means of balancing the carbon cycle, but we found them and started using them," said Sir David, adding that he blamed the introduction of steam energy for the start of human-induced climate change. "We now have 6.2 billion people and growing," he said. "The population is unlikely to plateau below nine billion, so we have to anticipate an ever-growing demand for energy, both from population growth and rises in GDP."
He reminded the audience of ice melting in the Arctic, Antarctic, China, and Mount Kilimanjaro, and cited a compelling array of statistics on the accelerating rise in carbon dioxide levels. For example, a three-kilometre ice-core from the Antarctic carrying information on carbon dioxide levels over the past 775,000 years showed fluctuations matching those yielded by ocean sediments.
"In every warm period, the carbon dioxide levels were 250 to 275 parts per million, while in every Ice Age they were 190 to 200," he said. In recent decades this figure has been sharply rising.
He said that burning fossil fuels was the cause of about three-quarters of carbon dioxide, with de-afforestation responsible for the rest. While it was not possible to say with 100 per cent accuracy that any individual extreme weather event was caused by global warming, such events were occurring more often - for example the European heat wave in 2003 that caused 30,000 deaths.
"There is a 90 per cent certainty that half of that severe heat in 2003 can be attributed to global warming," he said. "And the numbers of deaths could have been substantially decreased if the risks had been managed - this is frustrating for scientists who are trying to get the message across."
The problem is that even if we substantially cut carbon dioxide emissions now, the benefits will not be felt for 30 years, he said. The British government has been advised to work from a broad menu of solutions, including the use of wave energy, wind energy, biomass and photovoltaic sources. Emissions from cars should be lowered, buildings should be designed to be more efficient, and nuclear fusion is a possibility in about 30 years time.
In a pre-discourse interview with The Irish Times, Sir David said that the UK government would not be investing in new nuclear reactors, but commercial companies could make a case to do so themselves. He also said that Irish cities were at increased risk of flooding, broadly in line with the UK risk.