As temperature increases the range of disease carrying organisms has been increasing. Mosquitoes, in particular, more easily thrive in warmer and wetter environments. Hence, mosquitoes are been found more frequently at higher altitudes and, generally, further from the equator. In the U.S. , dengue fever and malaria cases are being found further north and west Nile has spread rapidly in the U.S. after the initial cases in NYC - while the number of West Nile cases are still small there is no preventive or curative treatment. Similarly, yellow fever could be reintroduced and become a serious health threat in the U.S. – cholera likewise. Also, tick borne diseases like Lyme disease have been spreading (worldwide) but are so far limited in the U.S. to areas near the coast from Maryland north into Maine as well as Wisconsin and Minnesota. Lyme disease is also now established in Canada. Up to 20% of Lyme sufferers have symptoms that are profound for many years. Amoebic diseases like naegleria fowleri are becoming more common in warm freshwater in the American southeast. Similarly, ciguatera fish poisoning is now endemic in the waters around Florida and spreading as the ocean warms northward along the East coast.
Current low-end estimates of species extinctions as a result of the current global warming are from 1/3 to 2/5 of all species. Since there are relatively few baseline numbers (before warming accelerated after 1950) for the vast majorities of species, especially for insects, etc., it is difficult to validly measure the extinction rate for a stable climactic environment. However, it is clear that species that have evolved for the stable climate of the past 10,000 years will be challenged by the warming. In particular, species that have evolved to live at cooler altitude temperatures generally face extinction along with species in the warming Arctic, e.g. polar bears. One consequence of the our warming atmosphere is that marine species are under pressure from oceanic warming as well as increasing ocean acidity. Evidence is accumulating that these conditions are promoting the greatest change in marine species in at least the last three million years and perhaps in three hundred million years. If warming becomes large, e.g. 15 degrees Fahrenheit, over time, it will likely produce an extinction rate above 90%, defining a new geologic era.
Infrastructure degradation from warming and the consequent stresses on varied services that we depend upon extends throughout our taken-for-granted way of life in all societies. In the affluent societies, we depend upon a very extensive and costly infrastructure. Roadways and their drainage structure as well as underlying water culverts, bridges, railways beds etc. and airports are all vulnerable to heat and/or extreme weather events. Higher temperatures (than originally designed for) or flooding will require redesign (and greater investment) for a constantly changing climactic environment.
The current power grid, especially above ground, is vulnerable to extreme weather, e.g. the last Northeast black-out, and will certainly be redesigned for a future of renewable rather than fossil fuel energy sources. Innumerable institutional components of our civilizational infrastructure face difficult challenges in an environment of constant change - for example, the health system is organized around hospitals or clinics which require power, adequate supplies (especially medication etc.) as well as transportation links. The response of communities to weather driven emergencies is slowly changing – but , in the U.S. and elsewhere, there will have to be a recognition that weather related “disasters” will occur with increasing frequency . The notion of the social infrastructure, e.g. between formal organizations etc. as well as between members of communities, needs to receive vastly increased attention as warming and climate change continues. In addition to an increased number of emergency responders, communities will need to prepare for new kinds of intra ad inter-community relationship/assistance as extreme weather events become more common and severe. The informal social structure of communities is a key focal issue as we move into a future of changing rather than predictable climate events.
Intrastate and interstate conflict over resources will unquestionably increase under the pressures from warming and climate change. Water and food are of course the most fundamental resources for any society - clothing and protection from the weather are also needed but vary greatly across physical locations. Valued resources of most kinds and climactic events are, generally, not restricted within political “boundaries” and increase the likelihood of conflict. Although climate change may not be the immediate cause of conflict, e.g. in the case of religious or ethnic conflicts, climate change is easily understood as a factor that can amplify discontents, disagreements and conflicts. For example, the effects of changing climate by 1980 can be seen as factors in many of the conflicts in East Africa, Kyrgyzstan, Pakistan and India, Brazil and Mexico. Further, the destabilizing conflicts of the Arab Spring and also their legacies to this time have also some roots in climate change. In particular, Syria experienced a most severe drought from 2006-2011 preceding the Arab Spring. As we can see today, a high enough level of conflict results in increased emigration, e.g. from Syria. The current migration issue is a foretaste of a phenomenon that will become increasing common in a warming world and it will challenge our taken-for-granted view of political boundaries and national sovereign rights.
The worldwide warming crisis poses the challenge of developing new international relationships to adapt to the future for the wellbeing of humanity as a whole.
State governments do not always have the legitimated power to insure public safety, e.g. Somalia, or the resources, e.g. the healthcare system in Guinea etc. during the Ebola 2014-15 epidemic, to insure public safety. Analogously, climate events may overwhelm governmental ability to recover, e.g. Louisiana after Katrina, without crucial outside help. This is the norm – local communities, States, poorer nations, e.g. Bangladesh, cannot successfully recover without outside help. As sea level rises and extreme weather events become more common and more severe the modern nation-state world will change. Environmental migration , e.g. from the nearest sea level members of the Alliance of Small Island States such as the Maldives and Marshall Islands as well as many poorer nation of the Sahel ad East Africa, has been steadily increasing. Where will the 163,000,000 inhabitants of Bangladesh go as sea level rises? There are at least 2 billion people in areas undergoing desertification. Europe is just now broaching the discussion of the large scale migration that is one aspect of our planetary future. How rapidly global temperature rises will determine how rapidly the human community will have to deal with the reality of increasing state collapse (i.e. the inability to provide for the well-being of the citizens) and out migration.