Scientists have been able to calculate the velocity of climate change on land and ocean environments using temperature records to determine isotherms and their change in a fifty year period from 1960 to 2009. So how fast are climate envelopes moving? The general median answer is 27.3 km/decade on land, and 21.7 km/decade in the ocean. This equates to a speed needed to outrun climate change on land (2.7 kilometers per year) and in the oceans (2.2 kilometers per year). This rate of movement of thermal climate envelopes poses problems for species facing a high speed migration, or a difficult and abrupt adaptation or extinction.
Here is how scientists measured the velocity of climate change ocurring:
We used global surface temperatures over 50 years (1960-2009) to calculate the distribution of the velocity and seasonal shifts of isotherm migration over land and ocean on a 1°-by-1° grid. The velocity of climate change (in km/year) was calculated as the ratio of the long-term temperature trend (in °C/year) to the two-dimensional spatial gradient in temperature (in °C/km, calculated over a 3°-by-3° grid), oriented along the spatial gradient. We introduced the seasonal climate shift (in days/decade) as the ratio of the long-term temperature trend (°C/year) to the seasonal rate of change in temperature (°C/day). We present seasonal shifts for spring and fall globally using April and October temperatures.
