What is the potential level of positive feedback that may come with the release of methane in the permafrost regions and continental shelves?

Given the potency of methane as a greenhouse gas, and also given the tremendous amount of methane stored both in the permafrost regions as well as the continental shelves, critical research needs to be done as to the level of positive feedback that may occur as some of this methane being released.

Massive releases of methane in earth’s past have played a pivotal role in dictating the direction and degree of climate change. While much attention has been given to carbon dioxide releases and sequestration, only a few scientists are currently studying methane releases going on in the thawing permafrost regions. Much more research needs to be conducted. The obstacles to doing this will be to move the focus of the press and policy makers from primarily carbon dioxide, to methane, as it is far more potent a greenhouse gas, and much more prone to significant positive feedback loops.

What are the feed back mechanisms between biodiversity and climate, how will they change over the next decades and what are the consequences?

Climate change and biodiversity change are interacting in feed-back loops that are poorly understood and unquantified and modelled. This applies to changing land (agriculture, desertification, cities, etc), and oceans (colour and physical stability of the ocean surface, acidification and calcifying organisms etc.) alike. The changing physico-chemical environment will exert important selective pressures on biological species and communities. Extinction of vulnerable species and explosions of adapted species are to be expected. They will change surface characteristics such as temperature, colour and albedo, gas exchange and atmospheric composition (CO2, NOx, methane). To predict the consequences a good understanding of these feed-back mechanisms is required, both on land and in the oceans.ue

How can we understand and best manage the feedbacks between (a) the growth and closer integration of the global economy and (b) changes in the biosphere, hydrosphere and atmosphere?

While it is important to understand environmental changes that are independent of human behavior, the most fundamental research questions facing us concern the large-scale environmental changes induced by human behavior, and that in turn induce an alteration in that behavior. These are the changes over which human societies have some control. The sustainability of global demographic and economic change depends on this set of feedbacks.

Demographic and economic changes have multiple and interconnected environmental impacts, but our understanding of these impacts is typically partial. The global change research programs, for example, tend to address subsets of impacts. At the same time human adaptation to environmental change tends to be problem specific – focusing separately on, for example, climate, biodiversity or disease risks. Understanding the interconnections between environmental changes and human responses to those changes is critical to the development of management strategies at the appropriate scale. It requires a research effort that spans the global change programs, and that embeds the adaptation and mitigation strategies adopted by human societies within that research effort.

What is the role of the biosphere in regulating climate, and which systems and processes are most influential?

Climate models tend to include interactions with the biosphere quite generally, yet the ecological and evolutionary responses and feedbacks are potentially very significant but hard to predict. An obstacle is that we probably don’t know enough about the processes to develop better models until more relevant basic research has been undertaken.

How will climate change effect the major Cycles of Carbon, Nitrogen and Sulphur and what kind of feedback on organism level is expected?

The increase of C02 has major consequences for plant growth (mainly positive) but can have drastic effects in oceans (reduction of pH). Only little is known about how the other cycles (Nitrogen/Sulphur) are effected by the increase of CO2.

Does silicate weathering, the hypothesized feedback mechanism for stabilizing atmospheric CO2 concentrations on geologic time scales, demonstrably increase with the observed increase in atmospheric CO2 concentrations?

Over then next 50-100 years, while atmospheric CO2 concentrations continue to increase, we are in the unique position to test whether the silicate weathering feedback mechanism exerts the hypothesized control on atmospheric carbon dioxide concentrations. The groundwork for answering this question has to be laid now to be able to track the response of the “critical zone” (biotic and abiotic weathering and erosion processes, including land-to-sea transport of weathering products) to changing global environmental conditions. One of the challenges is to distinguish the “natural” response of the Earth System from ongoing anthropogenic modifications of this system.