Here is the copy and pasted text of Article 3.3.1 of the International Panel on Climate Change's latest report on global warming (warning: get your Prozac ready):
3.3.1 Impacts on systems and sectors
The resilience of many ecosystems is likely to be exceeded this
century by an unprecedented combination of climate change,
associated disturbances (e.g. flooding, drought, wildfire, insects,
ocean acidification) and other global change drivers (e.g. landuse
change, pollution, fragmentation of natural systems, overexploitation
Over the course of this century, net carbon uptake by terrestrial
ecosystems is likely to peak before mid-century and then weaken
or even reverse, thus amplifying climate change.
Approximately 20 to 30% of plant and animal species assessed
so far are likely to be at increased risk of extinction if increases
in global average temperature exceed 1.5 to 2.5°C (medium confidence).
For increases in global average temperature exceeding 1.5 to
2.5°C and in concomitant atmospheric CO2 concentrations, there
are projected to be major changes in ecosystem structure and
function, species’ ecological interactions and shifts in species’
geographical ranges, with predominantly negative consequences
for biodiversity and ecosystem goods and services, e.g. water
and food supply.
Crop productivity is projected to increase slightly at mid- to
high latitudes for local mean temperature increases of up to 1
to 3°C depending on the crop, and then decrease beyond that in
some regions (medium confidence).
At lower latitudes, especially in seasonally dry and tropical
regions, crop productivity is projected to decrease for even small
local temperature increases (1 to 2°C), which would increase
the risk of hunger (medium confidence).
Globally, the potential for food production is projected to increase
with increases in local average temperature over a range
of 1 to 3°C, but above this it is projected to decrease (medium
Coasts are projected to be exposed to increasing risks, including
coastal erosion, due to climate change and sea level rise.
The effect will be exacerbated by increasing human-induced
pressures on coastal areas (very high confidence).
By the 2080s, many millions more people than today are projected
to experience floods every year due to sea level rise. The
numbers affected will be largest in the densely populated and
low-lying megadeltas of Asia and Africa while small islands
are especially vulnerable (very high confidence).
Industry, settlements and society
The most vulnerable industries, settlements and societies are
generally those in coastal and river flood plains, those whose
economies are closely linked with climate-sensitive resources
and those in areas prone to extreme weather events, especially
where rapid urbanisation is occurring.
Poor communities can be especially vulnerable, in particular
those concentrated in high-risk areas.
The health status of millions of people is projected to be affected
through, for example, increases in malnutrition; increased
deaths, diseases and injury due to extreme weather events; increased
burden of diarrhoeal diseases; increased frequency of
cardio-respiratory diseases due to higher concentrations of
ground-level ozone in urban areas related to climate change;
and the altered spatial distribution of some infectious diseases.
Climate change is projected to bring some benefits in temperate
areas, such as fewer deaths from cold exposure, and some
mixed effects such as changes in range and transmission potential
of malaria in Africa. Overall it is expected that benefits will
be outweighed by the negative health effects of rising temperatures,
especially in developing countries.
Critically important will be factors that directly shape the health
of populations such as education, health care, public health initiatives,
and infrastructure and economic development.
Water impacts are key for all sectors and regions. These are
discussed below in the Box ‘Climate change and water’.
Climate change is expected to exacerbate current stresses on water resources from population growth and economic and land-use change, including urbanisation. On a regional scale, mountain snow pack, glaciers and small ice caps play a crucial role in freshwater availability. Widespread mass losses from glaciers and reductions in snow cover over recent decades are projected to accelerate throughout the 21st century, reducing water availability, hydropower potential, and changing seasonality of flows in regions supplied by meltwater from major mountain ranges (e.g. Hindu-Kush, Himalaya, Andes), where more than one-sixth of the world population currently
Changes in precipitation (Figure 3.3) and temperature (Figure 3.2) lead to changes in runoff (Figure 3.5) and water availability. Runoff is projected with high confidence to increase by 10 to 40% by mid-century at higher latitudes and in some wet tropical areas, including populous areas in East and South-East Asia, and decrease by 10 to 30% over some dry regions at mid-latitudes and dry tropics, due to decreases in rainfall and higher rates of evapotranspiration. There is also high confidence that many semi-arid areas (e.g. the Mediterranean Basin, western United States, southern Africa and north-eastern Brazil) will suffer a decrease in water resources
due to climate change. Drought-affected areas are projected to increase in extent, with the potential for adverse impacts on multiple sectors, e.g. agriculture, water supply, energy production and health. Regionally, large increases in irrigation water demand as
a result of climate changes are projected.
The negative impacts of climate change on freshwater systems outweigh its benefits (high confidence). Areas in which runoff is projected to decline face a reduction in the value of the services provided by water resources (very high confidence). The beneficial impacts of increased annual runoff in some areas are likely to be tempered by negative effects of increased precipitation variability and seasonal runoff shifts on water supply, water quality and flood risk.
Available research suggests a significant future increase in heavy rainfall events in many regions, including some in which the mean rainfall is projected to decrease. The resulting increased flood risk poses challenges to society, physical infrastructure and water quality. It is likely that up to 20% of the world population will live in areas where river flood potential could increase by the 2080s. Increases in the frequency and severity of floods and droughts are projected to adversely affect sustainable development. Increased temperatures will further affect the physical, chemical and biological properties of freshwater lakes and rivers, with predominantly adverse impacts on
many individual freshwater species, community composition and water quality. In coastal areas, sea level rise will exacerbate water resource constraints due to increased salinisation of groundwater supplies.