IPCC’s 5th Assessment Report is out. It’s a long, exhausting document that I will probably slog my way through little by little. I’ve pulled out just a couple passages here about food production and fisheries, which are two risks I tend to think about. I think humans can generally deal with higher temperatures and more frequent storms and coastal flooding, because there is such a wide range of these things now and we deal with them. Food production is the intersection of water, energy, and ecosystems.

Assessment of many studies covering a wide range of regions and crops shows that negative impacts of climate change on crop yields have been more common than positive impacts (high confidence). The smaller number of studies showing positive impacts relate mainly to high-latitude regions, though it is not yet clear whether the balance of impacts has been negative or positive in these regions (high confidence). Climate change has negatively affected wheat and maize yields for many regions and in the global aggregate (medium confidence). Effects on rice and soybean yield have been smaller in major production regions and globally, with a median change of zero across all available data, which are fewer for soy compared to the other crops. (See Figure 1.11C) Observed impacts relate mainly to production aspects of food security rather than access or other components of food security. Since AR4, several periods of rapid food and cereal price increases following climate extremes in key producing regions indicate a sensitivity of current markets to climate extremes among other factors (medium confidence)…

Global marine species redistribution and marine biodiversity reduction in sensitive regions, under climate change, will challenge the sustained provision of fisheries productivity and other ecosystem services, especially at low latitudes (high confidence). By the mid-21st century, under 2 °C global warming relative to pre-industrial temperatures, shifts in the geographical range of marine species will cause species richness and fisheries catch potential to increase, on average, at mid and high latitudes (high confidence) and to decrease at tropical latitudes and in semi-enclosed seas (Figure 2.6A) (medium confidence). The progressive expansion of Oxygen Minimum Zones and anoxic ‘dead zones’ in the oceans will further constrain fish habitats (medium confidence). Open-ocean net primary production is projected to redistribute and to decrease globally, by 2100, under all RCP scenarios (medium confidence). Climate change adds to the threats of over-fishing and other non-climatic stressors (high confidence).

We talk so much about the atmosphere, but our oceans, forests, and soils are absorbing a lot of the carbon emissions, and are the reason our planet and current civilization are as resilient as they are. We better take care of them.