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IPCC Report 2: Summary

The second report by the Intergovernmental Panel on Climate Change was published on 6th April 2007. Whereas the first report showed the scientific basis for the belief that man is changing the climate, the second report showed the physical the effects of climate change.

The Scope of the Report

The report stated that, "The Assessment is of current scientific understanding of impacts of climate change on natural, managed and human systems, the capacity of these systems to adapt and their vulnerability".

The report defined Adaptive Capacity as, "the ability of a system to adjust to climate change (including climate variability and extremes) to moderate potential damages, to take advantage of opportunities, or to cope with the consequences".

It defined Vulnerability as, "the degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change, including climate variability and extremes. Vulnerability is the function of the character, magnitude and rate of climate change and variation to which a system is exposed, its sensitivity, and its adaptive capacity".

You can read the summary of the first report by the IPCC by clicking here.

Current Knowledge about Observed Impacts of Climate Change on the Natural and Human Environment

This first part of the report covers data collected since about 1970 to the present day. The data is mainly in the form of observations of the effects of climate change that have already happened.

The following are statements from the report:

"Observational evidence from all continents and most oceans shows that many natural systems are being effected by regional climate changes, particularly temperature increases."

"A global assessment of data since 1970 has shown it is likely that anthropogenic warming has had a discernable influence on many physical and biological systems."

"Other effects of regional climate changes on natural and human environments are emerging, although many are difficult to discern due to adaptation and non-climatic drivers."

Current Knowledge about the Future Impacts of Climate Change

The next section of the report concerns the projected impacts of climate change in the future. Here are the key statements:

Fresh Water Resources and their Management

"By mid-century, annual average river run-off and water availability are projected to increase by 10-40% at high latitudes and in some wet tropical areas, and decrease by 10-30% over some dry regions at mid-latitudes and in the dry tropics, some of which are presently water stressed areas."

"Drought-affected areas will likely increase in extent. Heavy precipitation, which are very likely to increase in frequency, will augment flood risk. "

"In the course of the century, water supplies stored in glaciers and snow cover are projected to decline, reducing water availability in regions supplied by meltwater from major mountain ranges, where more than one-sixth of the world's population lives. "

Ecosystems

"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. land use, pollution, over-exploitation of resources). "

"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 20-30% of plant and animal species assessed so far are likely to be at increased risk of extinction if increases in global average temperature exceed 1.5-2.5°C. "

"For increases in global average temperature exceeding 1.5-2.5°C and in concomitant atmospheric carbon dioxide concentrations, there are projected to be major changes in ecosystem structure and function, species' ecological interactions, and species' geographic ranges, with predominantly negative consequences for biodiversity, and ecosystem goods and services e.g., water and food supplies. "

"The progressive acidification of oceans due to increasing atmospheric carbon dioxide is expected to have negative impacts on marine shell forming organisms (e.g. corals) and their dependent species."

Food, Fibre and Forest Functions

"Crop productivity is projected to increase slightly at mid to high latitudes for local mean temperature increases of up to 1-3°C depending on the crop, and then decrease beyond that in some regions."

"At lower latitudes, especially seasonally dry and tropical regions, crop productivity is projected to decrease for even small local temperature increases (1-2°C), which would increase the risk of hunger."

"Globally, the potential for food production is projected to increase with increases in local average temperature over a range of 1-3°C, but above this it is expected to decrease. "

Coastal Systems and Low-Lying Areas

"Coasts are projected to be exposed to increasing risks, including coastal erosion, due to climate change and sea-level rise and the effect will be exacerbated by increasing human-induced pressures on coastal areas. "

"Corals are vulnerable to thermal stress and have low adaptive capacity. Increases in sea surface temperature of about 1-3°C are projected to result in more coral bleaching events and widespread mortality, unless there is thermal adaptation or acclimatisation by corals. "

"Coastal wetlands including salt marshes and mangroves are projected to be negatively affected by sea-level rise especially where they are constrained on their landward side, or starved of sediment. "

"Many millions more people are projected to be flooded every year due to sea-level rise by the 2080s. Those densely populated and low-lying areas where adaptive capacity is relatively low, and which already face other challenges such as tropical storms or local coastal subsidence, are especially at risk. The numbers affected will be largest in the mega-deltas of Asia and Africa while small islands are especially vulnerable. "

"Adaptation for coastal regions will be more challenging in developing countries than developed countries due to constraints on adaptive capacity. "

Industry, Settlement and Society

"Costs and benefits of climate change for industry, settlement, and society will vary wildly by location and scale. In the aggregate, however, net effects will tend to be more negative the larger the change in climate."

Health

"Projected climate change-related exposures are likely to affect the health status of millions of people, particularly those with low adaptive capacity, through:

• increases in malnutrition and consequent disorders, with implications for child growth and development;
• increases in deaths, disease and injury due to heat waves, floods, storms, fires and droughts;
• the increased burden of diarrhoeal disease;
• the increased frequency of cardio-respiratory diseases due to higher concentrations of ground level ozone related to climate change; and,
• the altered spatial distribution of some infectious disease vectors"

"Climate change is expected to have some mixed effects, such as the decrease or increase of the range and transmission potential of malaria in Africa."

Africa

"By 2020, between 75 and 250 million people are projected to be exposed to an increase in water stress due to climate change. If coupled with increased demand, this will adversely affect livelihoods and exacerbate water-related problems. "

"Agricultural production, including access to food, in many African countries and regions is projected to be severely compromised by climate variability and change. The area suitable for agriculture, the length of the growing seasons and yield potential, particularly along the margins of semi-arid and arid areas, are expected to decrease. This would further adversely affect food security and exacerbate malnutrition in the continent. In some countries, yields from rain-fed agriculture could be reduced by up to 50% by 2020. "

Asia

"Glacial melt in the Himalayas is projected to increase flooding, rock avalanches from destabilised slopes, and affect water resources within the next two to three decades. This will be followed by decreased river flows as the glaciers recede. "

"Freshwater availability in Central, South, East and Southeast Asia particularly in large river basins is projected to decrease due to climate change which, along with population growth and increasing demand arising from higher standards of living, could adversely affect more than a billion people by the 2050s. "

"Climate change is projected to impinge on sustainable development of most developing countries as it compounds the pressure on natural resources and the environment associated with rapid urbanisation, industrialisation, and economic development. "

Australia and New Zealand

"As a result of reduced precipitation and increased evaporation, water security problems are projected to intensify by 2030 in southern and eastern Australia and, in New Zealand, in Northland and some eastern regions. "

"Significant loss of biodiversity is projected to occur by 2020 in some ecologically-rich sites including the Great Barrier Reef and Queensland Wet Tropics. Other sites at risk include Kakadu wetlands, south-west Australia, sub-Antarctic islands and the alpine areas of both countries. "

Europe

"For the first time, wide ranging impacts of changes in current climate have been documented: retreating glaciers, longer growing seasons, shift of species ranges, and health impacts due to a heat wave of unprecedented magnitude. The observed changes described above are consistent with those projected for future climate change. "

"In Southern Europe, climate change is projected to worsen conditions (high temperatures and drought) in a region already vulnerable to climate variability, and to reduce water availability, hydropower potential, summer tourism, and in general, crop productivity. It is also projected to increase health risks due to heat waves and the frequency of wildfires. "

"In Central and Eastern Europe, summer precipitation is projected to decrease, causing higher water stress. Health risks due to heat waves are projected to increase. Forest productivity is expected to decline and the frequency of peatland fires to increase. "

"In Northern Europe, climate change is initially projected to bring mixed effects, including some benefits such as reduced demand for heating, increased crop yields and increased forest growth. However, as climate change continues, its negative impacts (including more frequent winter floods, endangered ecosystems and increasing ground instability) are likely to outweigh its benefits. "

Latin America

"By mid-century, increases in temperature and associated decreases in soil water are projected to lead to gradual replacement of tropical forests by savannah in eastern Amazonia. Semi-arid vegetation will tend to be replaced by arid-land vegetation. There is a risk of significant biodiversity loss through species extinction in many areas of tropical Latin America. "

"In drier areas, climate change is expected to lead to salinisation and desertification of agricultural land. Productivity of some important crops are projected to decrease and livestock productivity to decline, with adverse consequences for food security. In temperate zones soybean yields are projected to increase. "

"Sea-level rise is projected to cause increased risk of flooding in low-lying areas. Increases in sea surface temperature due to climate change are projected to have adverse effects on Mesoamerican coral reef, and cause shifts in the location of south-east Pacific fish stocks. "

"Changes in precipitation patterns and the disappearance of glaciers are projected to significantly effect water availability for human consumption, agriculture and energy generation. "

North America

"Moderate climate change in the early decades of the century is projected to increase aggregate yields of rain-fed agriculture by 5-20%, but with important variability among regions. Major challenges are projected for crops that are near the warm end of their suitability range or depend on highly utilised water resources."

"Warming in western mountains is projected to cause decreased snowpack, more winter flooding, and reduced summer flow, exacerbated competition for over-allocated water resources."

"Disturbances from pests, disease, and fire are projected to have increasing impacts on forests, with and extended period of high fire risk and large increases in area burned. "

"Cities that currently experience heat waves are expected to be further challenged by an increased number, intensity and duration of heat waves during the course of the century, with potential for adverse health impacts. The growing number of the elderly population is most at risk. "

Polar Regions

"In the Polar Regions, the main projected biophysical effects are reductions in thickness and extent of glaciers and ice sheets, and changes in natural ecosystems with detrimental effects on many organisms including migratory birds, mammals and higher predators. In the Arctic, additional impacts include reductions in the extent of sea ice and permafrost, increased coastal erosion, and an increase in the depth of permafrost seasonal thawing."

"In both polar regions, specific ecosystems and habitats are projected to be vulnerable, as climatic barriers to species' invasions are lowered. "

Small Islands

"Small islands, whether located in the Tropics or higher latitudes, have characteristics which make them especially vulnerable to the effects of climate change, sea level rises and extreme effects. "

"Deterioration in coastal conditions, for example through coastal erosion of beaches and coral bleaching, is expected to affect local resources, e.g. fisheries, and reduce the value of these destinations for tourism. "

"Sea-level rise is expected to exacerbate inundation, storm surge, erosion and other coastal hazards, thus threatening the vital infrastructure, settlements and facilities that support the livelihood of island communities."

"Climate change is projected by the mid-century to reduce water resources in many small islands, e.g., in the Caribbean and Pacific, to the point where they become insufficient to meet demand during low-rainfall periods. "

"With higher temperatures, increased invasion by non-native species is expected to occur, particularly on middle and high-latitude islands. "

Current Knowledge About Responding to Climate Change

"Some adaptation is occurring now, to observed and projected future climate change, but on a limited basis. "

"Adaptation will be necessary to address impacts resulting from warming which is already unavoidable due to past emissions. "

"A wide array of adaptation options is available, but more extensive adaptation than is currently occurring is required to reduce vulnerability to future climate change. There are barriers, limits and costs, but these are not fully understood. "

"Vulnerability to climate change can be exacerbated by the presence of other stresses. "

"Future vulnerability depends not only on climate change but also on development pathway. "

"Sustainable development can reduce vulnerability to climate change, and climate change could impede nations' abilities to achieve sustainable development pathways. "

"Many impacts can be avoided, reduced or delayed by mitigation. "

"A portfolio of adaptation and mitigation measures can diminish the risks associated with climate change. "

"Impacts of climate change will vary regionally but, aggregated and discounted to the present, they are very unlikely to impose net annual costs which will increase over time as global temperature increases."

The Full IPCC Report

You can download the full version of the report (in PDF format) from the IPCC website.