IPCC AR5 WGI Chapter 14 - A Review
Climate Phenomena and their Relevance for Future Regional Climate Change
Content Summary
Introduction
This chapter summarizes the major climate phenomena that influence regional climate and assesses how these phenomena are expected to change in a warming climate. This discussion sets the stage for the final section of the chapter, which summarizes projected changes in temperature and precipitation region-by-region across the globe. These projections take into account the aforementioned climate phenomena, as they are very important factors on the regional scale.
Regional climate is strongly influenced by modes of climate variability. Modes provide simplified descriptions of variations in the climate system, and may respond to climate change in one or more of the following ways (from the IPCC report, pg. 1222-1223):
• No change—the modes will continue to behave as they have done in the recent past.
• Index changes—the probability distributions of the mode indices may change (e.g., shifts in the mean and/or variance, or more com- plex changes in shape such as changes in local probability density, e.g., frequency of regimes).
• Spatial changes—the climate patterns associated with the modes may change spatially (e.g., new flavours of ENSO; see Section 14.4 and Supplementary Material) or the local amplitudes of the climate patterns may change (e.g., enhanced precipitation for a given change in index (Bulic and Kucharski, 2012)).
• Structural changes—the types and number of modes and their mutual dependencies may change; completely new modes could in principle emerge.
The IPCC report uses very calculated language to ascribe a probability and confidence level to their statements. Their guidelines for this are shown below:
Chapter Sections
14.1. Introduction
14.2. Monsoon Systems
14.3. Tropical Phenomena
14.4. El Niño-Southern Oscillation (ENSO)
14.5. Annular and Dipolar Modes
14.6. Large-Scale Storm Systems
