For world food security and Arctic methane feedback what natters most is the summer Arctic and N. hemisphere, which have warmed a lot this past decade compared to a few decades ago.
Large regions of NH food production and permafrost are warming fast.
We must consider the temperature change of different regions to assess global warming danger.
The NASA map of the trend of summer warming for the past decade shows fastest warming over a third the US below the Great Lakes, Canada permafrost, Eastern Europe and Russia (high food production) and a huge region of Siberian permafrost
The most important region by far is the Arctic - because of all the carbon the Arctic holds, till now safely cold and frozen. In the case of the Arctic the temperature increase has not stalled- it has gone on increasing at a rapid rate. Now the Arctic is warming 3X the global average. That means increasing Arctic methane emissions, and also CO2 and nitrous oxide. This increased warming of the Arctic is what matters most because it can lead to the planetary catastrophe of GHG feedback rapid global warming and runaway climate change.
While the temperature increase may have slowed to 2012, the decade was the warmest ever.
Increased Radiative forcing (total heat in the climate system) correlates directly with the total increase in atmospheric GHGs. The NOAA converts the two into a GHG Index which provides a measure of the increase in GHG heat in the whole climate system. It is the best single index of warming to use.
Warming cannot stop because today's extreme high atmospheric GHGs has double today's global temperature in the climate system that has not registered yet.
CLIMATE EMERGENCY INSTITUTE
The Health and Human Rights Approach to Climate Change
THERE IS NO PAUSE/HIATUS IN GLOBAL WARMING
June 2015 latest research shows no pause
2014 was a record year for global warming, and the indications are that global warming is speeding up.
The different rates of warming in different regions is marked and projected to increase.
The Arctic is warming fastest which is a planetary emergency because the largest sources of carbon which release more carbon with warming - are in the Arctic.
Next comes Europe and N> America, a planetary emergency- the world's best food producing regions, where heat waves and drought are increasing
- Warming of the climate system is unequivocal
- Human influence on the climate system is clear
- Recent climate changes have had widespread impacts on human and natural systems.
IPCC AR5 2014 Headline Statements
This is global mean (land-sea) surface temperature increase, which rpresents only a very snall part of the heat being added to biospehere from greenhouse gas emissions accumuating in the atmopshere