QUEST
Planet Earth magazine editorial
An editorial from Planet Earth magazine, autumn 2002, by NERC's then Chief Executive, Professor John Lawton
My dictionary defines 'quest' as 'to go in search of something'. QUEST is also the acronym for a new NERC research programme Quantifying and Understanding the Earth System, highlighted in our strategy Science for a Sustainable Future. What are we looking for, and why highlight the search in the leader to Planet Earth?
QUEST will provide a co-ordinated effort to quantify and predict global and regional carbon budgets. Carbon moves through the Earth system in vast quantities. In data produced by the Mauna Loa observatory in Hawaii (where global carbon dioxide levels in the atmosphere have been monitored since 1959) you can see levels fall in spring as plants start to photosynthesise (taking up carbon dioxide), and rise again in autumn as leaves die and rot, releasing carbon dioxide back into the air. I find the graph mesmerising. In that simple trace you can see the whole biosphere 'at work'.
But the Mauna Loa trace also shows something else, namely a steady increase in carbon dioxide levels in the atmosphere from 315 ppmv (parts per million by volume) in 1959 to about 360 ppmv now. You know the rest of the story. The increase is due to human activities, primarily burning fossil fuel, releasing huge quantities of geologically stored carbon back into the atmosphere as carbon dioxide. And because carbon dioxide is a greenhouse gas, with an inevitability pointed out by Svante Arrhenius as long ago as 1896, the Earth is warming.
But within this grand scheme there are some big things that we do not know. We know how much fossil fuel humans burn every year, and hence how much carbon dioxide should appear in the atmosphere. But the actual quantity (measured by the Mauna Loa trace) is too small. This is where the uncertainties begin. Some carbon dioxide is taken up by the oceans (this 'sink' is reasonably well understood), and some by plants and ultimately soils on land. This terrestrial sink is poorly understood, and poorly quantified.
Why should we care about the terrestrial carbon sink? For several reasons. Under the Kyoto Protocol, many nations would like to count their terrestrial carbon sinks against their carbon dioxide emissions. But if we cannot accurately measure these sinks, how do you do that? More serious in the longer run, as the world warms, what will happen to terrestrial sinks? Will they become net sources of carbon dioxide? (It is not rocket science to say that things decompose faster at higher temperatures). Current, crude estimates suggest that the global terrestrial carbon sink could become a net source of carbon dioxide in roughly 50 years, giving a vicious, positive twist to global warming.
QUEST will seek to reduce these uncertainties, and to provide a more robust understanding of the global carbon cycle. A QUEST working group has been established to develop the programme, and a town meeting is planned for early December. QUEST will require partnerships, both within the UK, and between colleagues in Europe and the USA. NERC's planned investment in QUEST is substantial. It has to be if we are really to make a difference. It is difficult to think of a more important thing to search for.
John H. Lawton