• H2020
• Special Reports

“The feedback loops of the Atmosphere-Ecosystem boundary layer resemble a giant jigsaw puzzle. One should not lose the big picture, but find the tiniest, molecular-level pieces at the same time” says Anna Lintunen, FCoE ATM co-ordinator

By cleaning the air we could save human lives, but simultaneously accelerate climate change. The unpleasant conflict stems from complex feedback mechanisms of the atmosphere, many of which are still unknown .

Do we have to make an impossible choice between current and future generations? Atmospheric pollutants damage health and cause untimely deaths. This is an urgent problem to be solved, and there is no time to waste. On the other hand, elimination of some pollutants might result in unexpected and undesirable side effects in the climate. For example, chemical compounds like sulphuric acid promote the formation of aerosols which cool the atmosphere, thus protecting us from global warming.

Is there anything we can do? Actually, there is. We can choose an optimal selection of policy and technical actions if we know the chemical reactions and microphysical processes of the atmosphere deeply enough. We ought specifically to study the complex interactions of the atmosphere and the rest of the ecosystem, e.g. the vegetation and soil.

This is exactly the core question studied by almost 200 physicists, chemists, meteorologists and forest scientists in the FCoE ATM, the Finnish Center of Excellence in Atmospheric Science. They drill into molecules both theoretically and experimentally, using all means from computerised quantum chemistry to laboratory and field work.

Understanding by quantification  

The atmospheric scientists aim at quantifying the feedback loops between the atmosphere and the ecosystem. Quantification means that a phenomenon is described as numbers or equations. Scientists often succeed in constructing many interlinked equations that form a model. A quantified model can be empirically tested, and it can be used for predicting purposes. Careful quantification is, thus, a prerequisite for reaching the ultimate aim of the atmospheric scientists: to reduce the uncertainties connected with current climate scenarios.

To build and test a model empirically, the scientists need measurement data. Fortunately, the Finnish Center of Excellence has several well-equipped observational stations at their disposal. The famous Station for Measuring Ecosystem-Atmosphere Relations (SMEAR) stations, located in Finland, Estonia and China, are essentially large laboratories positioned in different terrains.

But how can all these equations and formal knowledge be applied to solve practical climate policy problems? Jaana Bäck is a professor of Forest-Atmosphere Interactions at the University of Helsinki, and works for FCoE ATM, too. She gives a concrete example:

“With the help of this knowledge we find out in what way the carbon-absorbing ability of the forests should be accelerated. We could, for example, choose which species of trees to plant according to their ability of emitting certain chemical compounds. Many of them promote the formation and growth of aerosols, of which a certain part cool the atmosphere.”

Academy professor Markku Kulmala concurs:

“To put it simply, by making the right choices about the order of cleaning actions we would save money, the environment and human lives. Why would we not take advantage of the fact that in some respects Nature has some capacity of healing itself? The point is that without scientific means we do not know where this healing potential lies.”

Finally, Kulmala refers to climate engineering. “Current engineering technologies are far from perfect, and to use them might be risky. We scientists can not and must not decide whether the climate should be engineered or not. But it would be both immoral and stupid not to take a closer look at the basic chemical and physical processes of the atmosphere if it can be applied in promoting safer technologies.”

Mai Allo
Research Assistant
Dept of Physics
Uni of Helsinki, Finland
+358503199584, 50 650

Professor Markku Kulmala
Director
Department of Physics
University of Helsinki
+358 9191 50756

http://www.physics.helsinki.fi/english/