IPCC AR5 Working Group II Summary for Policymakers

The IPCC is well known for their tendency to leak documents before their final release, and the working group 2 of the AR5 is no exception. The summary for policymakers for the WG II deals primarily with the impacts, adaptations, and vulnerabilities of climate change, and here are some of the moreinteresting highlights of the summary:

• Transformative changes may be necessary as a response to projected climate changes: 

This might not sound like that big of a statement, until you read the IPCC’s definition for “transformation,”which is :

“A change in the fundamental attributes of a system, often based on altered paradigmsgoals, or values. Transformations can occur in technological or biological systems, financial structures, and regulatory, legislative, or administrative regimes.”

The IPCC report is acknowledging the possibility that sustainability might be impossible without a paradigm shift in our current global culture.

• Some ecosystems and human systems show "significant vulnerability" to climate variability: 

This is one point the IPCC is making with "very high confidence." This vulnerability is exacerbated in developing countries.

• Several major terrestrial ecosystems are undergoing broad-scale changes that can be characterized as early warnings for coming regime shifts, in part due to climate change:

One of the most inimical changes we expect from climate change is shifts in ecosystems. While some areas of northern latitude might shift from unproductive land to farm land, many regime shifts could be less welcome. Imagine Oklahoma drying up and becoming a permanent desert or the Amazon  Rainforest becoming a prairie. Many of these changes would release more carbon into the atmosphere, which could accelerate the warming already occurring.    

• Effects of climate change on food production are evident in several regions:

Much like the regime shifts, so far the negative effects of climate change on food production have been more negative than positive. This means that a future earth will have decreased food productivity as billions of people are added to the global population.

• Terrestrial and freshwater ecosystems can, when pushed by climate change, cross “tipping points” and abruptly change in composition, structure, and function. The crossing of these tipping points will result in significant increases in carbon emissions to the atmosphere: 

The idea of a tipping point makes the previous two predictions that much more ominous. The idea of non-linearity and “tipping points” means rapid changes which could happen at anytime and in the blink of an eye

• Key risks of associated with global mean temperature increase >4o C relative to preindustrial include exceedance of human physiological limits in some locations and nonlinear earth system responses: 

The 4o mark is shaping up to be a key determinant of the fate of humanity in a future earth. This threat is made that much more ominous with recent reports that indicate this temperature range is more probable than the lower end estimates.

• Animals and plants are adapting to climate change:

Unlike some humans in the United States, the larger biosphere is reacting to an actively changing climate. Animals and plants are changing their ranges and their abundance. While the evidence is still inconclusive, there is some indication that recent extinctions are attributable to this changing climate.

This is just some of the many new revelations in the report. This is perhaps the strongest position the IPCC has taken when addressing the severity of climate change and its potential impacts on the future of the world.