Global wildfires are decreasing over time

Implications for US National Security of Anticipated Climate Change. https://en.wikisource.org/wiki/Implications_for_US_National_Security_of_Anticipated_Climate_Change

failures, wildfires , energy blackouts, infrastructure breakdown, or infectious disease outbreaks. The frequency and magnitude of such events are increasing They could trigger crop failures, wildfires, energy blackouts, infrastructure breakdown, or infectious disease outbreaks. The frequency and magnitude of such events are increasing as the climate changes, according to the IPCC. Moreover, multiple weather disturbances—when several extreme weather events occur within a small region or short time—compound their impact while undercutting efforts by people and governments to cope. Clusters or rapid sequences of relatively modest weather events may cause more damage than very powerful single events. Global climatological stresses—such as sea-level rise, ocean acidification, permafrost and glacial melt, air quality degradation, changes in cloud cover, and sustained shifts in temperature and precipitation—could substantially alter broader natural and manmade systems involving where and how humans live and patterns of infectious disease outbreaks, as well as critical ecosystems. The following table lays out the IPCC baseline for likely increases in extreme weather events in the decades ahead. Such events may occur at different rates of frequency, intensity, and location compared to historical patterns, and lack of preparedness for those changes—such as weather-related disasters, drought, famine, supply chain breakdown, or damage to infrastructure—may prove a primary cause of disruption. According to the National Oceanic and Atmospheric Administration, weather reflects short-term conditions of the atmosphere in a particular region while climate encompasses the averages, variability, and other statistics of weather over longer periods of time. Countries with weak political institutions, poor economic conditions, or where other risk factors for political strife are already present will be the most vulnerable to climate-linked instability. In the most dramatic cases, state authority may collapse partially or entirely. Climate-related instability is likely to create strong pressure for foreign aid, disaster assistance, or military responses. Even if climate-related disruptions do not undermine stability, however, some  ​ governments could be so preoccupied with managing the effects that they have little time or energy left to engage on broader foreign policy issues. Sudden extreme weather—such as from floods, droughts, and severe tropical storms—almost certainly will increase the number of displaced people, particularly in regions that are unaccustomed to or unprepared for such events. Rising sea levels and unexpectedly large storm surges could threaten small island states and low-lying coastal regions—including many megacities—with flooding and saltwater contamination of freshwater. Over 20 years, the net effects of climate change on the patterns of global human movement and statelessness could be dramatic, perhaps unprecedented. Some forms of geoengineering experimentation are probably within the financial and technical capacity of some major powers and individuals, although there are fundamental scientific uncertainties about the efficacy and possible unintended consequences of such methods. If, for example, geoengineering methods suppressed global temperatures below the point assumed to bring dangerous climate change, such efforts would almost certainly need to be sustained and probably would alter global weather patterns, benefitting some regions at the expense of others, according to the National Academies of Science. The terrorist group Al-Shabaab exploited the 2011-13 famine in Somalia to coerce and tax international aid agencies, and it withheld food from those it deemed uncooperative, according to Human Rights Watch. In 2015, insurgent groups in northern Mali exploited deepening desertification, worsened by persistent drought, to enlist locals in a “food for jihad” arrangement. Heatwaves threaten livestock directly and also reduce fertility, decrease milk production, and make them more vulnerable to disease. Droughts, wildfires, and extended periods of reduced precipitation threaten pasture and food supplies, indirectly threatening livestock.   ​ Potential Climate Discontinuities and Secondary Surprises [ edit ] While current climate models project long-term increases in global average surface temperatures, climate scientists warn that more sudden, dramatic shifts could be possible, given the complexity of the system and analogs in the climate record. Looking back over the past 100,000 years, the earth’s climate periodically has undergone extreme shifts, sometimes in as little as a decade. Such abrupt swings can occur in complex systems when seemingly small shifts in the forces in play suddenly trigger dramatic nonlinear change, such as when a slight drop in temperature can suddenly turn water into ice. Future climate conditions could be altered significantly by government policies, industrial practices, or consumer behavior regarding greenhouse gas emissions. That said, IPCC scenario modeling suggests that aggressive environmental policies would not begin to slow the growth of global average surface temperatures for another 15-20 years because of the lag time for complex global climate systems to respond to changes in human behavior (see chart below). The long time horizon for climate change makes for different assessments of the national security implications for different periods.