"Hump weekend" at the COP  is dedicated to the biomes, with separate all day events focused on the role and effects of climate on oceans, forests , and agriculture.   Each of these biomes is fundamentally connected with the atmosphere and climate.   Higher CO2 concentrations and climate change can alter these systems in profound ways.  Warmer temperatures would lead to sea-level rise, both through melting ice surfaces and thermal expansion.  Higher CO2 concentrations are absorbed by the oceans, which helps regulate the atmospheric levels but also acidifies the ocean and weakens the calcification process, literally the backbone of sea life. 

Higher CO2and temperatures together can change in the species composition and areal extent of forest.  Changes in precipitation patterns and extreme heat stress can jeopardize the continued existence of certain forests.  There is concern about tropical forest "die back" under future climate scenarios, concern amplified by the fact that when forests die they return CO2 back to the atmosphere, exacerbating the problem that began the cycle. 

It should come as no shock that weather affects farming, as farmers have experience good years and bad years since men came out of the caves and started planting seeds.  Fixing the greenhouse gas emissions problem will not mean that every year is a good year.  But the higher temperatures and greater variability in precipitation foretells a future where there are more bad years than good.  Farmers are adaptive.  But it takes money to adapt.  And not all farmers in all places may have the money it takes (read Sub-Saharan Africa).    

These biomes also play an important part in the global carbon cycle - a role that can be modified to help mitigate climate threats.  The clearing of forests currently accounts for about one-seventh of global CO2 emissions, roughly the same as all planes, trains and automobiles on earth. Curtailing deforestation can play a significant role in the global mitigation portfolio, but these emissions are occurring mostly in the tropical developing countries, which complicates the issue of who should pay for the reductions.  The current negotiations on reduced emissions from deforestation and degradation (called REDD+) are trying to sort this out.   

Agriculture's global emissions - both carbon dioxide and other potent greenhouse gases such as methane and nitrous oxide - are of similar magnitude to forests and there are numerous ways to change practices to reduce emissions and retain carbon in soils.  But any emission-reducing agricultural practices that lower productivity are problematic for a land-constrained planet that expects to feed nine billion people by the middle of the century.  We need to grow more on less land rather than the other way around.  That is also a way to avoid deforestation, as most forest land is cleared for agricultural purposes.     So efforts to reduce emissions from agriculture and forests need to be coupled with efforts to increase agricultural productivity or change the mix of foods we eat.

One area that has gained attention more recently is "blue carbon" - the carbon stored in lands on the edge of the sea - mangroves, salt marshes and sea grasses.  Scientists are focusing more on the significant carbon consequences of the continued loss of these ecosystems and economists are trying to monetize these losses in order to develop payment schemes to keep them from happening. The negotiations have not yet taken on blue carbon mechanisms, but many in the conservation community seeking ways to reverse the heavy losses of these marine ecosystems will welcome any attention (and money) the global climate agreement can bring to the table.    

The interconnectedness of oceans, forests, agriculture and climate systems also creates interesting group dynamics in the climate talks.   As evidenced by the three Oceans, Forests and Agriculture Days events, each natural system has a constituency that is deep-seated and predates any involvement in the global climate discussions. Each constituency seems to welcome the attention that climate has brought to their issue, but they do not want the climate debate to define the terms of their own agenda.  For instance, forest advocates understand the grave threat that climate change poses for forests and they understand that slowing deforestation can also have tremendous climate benefit potential.  But they see forests as more than just carbon and many would not want carbon to be the sole determinant of how forests are managed - biodiversity, water provision and the support of forest-dependent communities are other important forest ecosystem services that can sometimes conflict with carbon objectives.  Likewise, agricultural groups stress their long-term efforts to enhance food security and consider this critical to any policy.  And while ocean groups are gravely concerned about the effect of rising sea temperatures and sea levels, they are at least equally as concerned about ocean acidification. Why this matters is that global climate policies focus on six different greenhouse gases, but acidification is caused by only one of them, CO2.  So the types of flexibilities in a global mechanism that might lead to higher CO2 emissions if methane emissions are lowered does not help the acidification issue.      

Climate policy is clearly the broadest in scope of any environmental policy ever attempted, but it is still not all-encompassing and cannot be seen as a single approach to cure all environmental problems.  Its primary focus needs to be on reducing climate threats cost-effectively and equitably and with due regard to the complex feedbacks between the climate systems and the rest of the biosphere.  Climate policy needs to be coordinated with policies that are more specifically focused on oceans, forests, agriculture and other critical ecosystems in order to achieve a more beneficial suite of environmental outcomes.  Negotiators need to be enlightened about these critical connections, but they run the risk of losing focus and momentum if they try to cover too many objectives with one policy framework.