Debate about climate change is about to, er, heat up, after the Intergovernmental Panel on Climate Change (IPCC) delivered its fifth assessment report, snappily known as WGII AR5.
The IPCC says both were compiled using “a substantially larger knowledge base of relevant scientific, technical, and socioeconomic literature”, adding that “increased literature has facilitated comprehensive assessment across a broader set of topics and sectors, with expanded coverage of human systems, adaptation, and the ocean.”
The document acknowledges that climate change is taking place and in various places points at human activity as the sort of thing that looks likely to get the climate shifting. Importantly, however, the report uses the following definition:
“Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions, and persistent anthropogenic changes in the composition of the atmosphere or in land use.”
The IPCC points out that its definition is rather different from that used by the United Nations Framework Convention on Climate Change, which defines the term as “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.”
This is not, therefore, a report trying to prove or disprove anthropogenic climate change theories. Instead, it's all about how the world responds to the shifting climate we find ourselves in.
The summary for policymakers alone is 44 pages and the full report contains 1,552, so it's necessary to be rather brief in this initial report on the newly-released documents. Later analysis is the place to go deeper. Let's start with the summary's assessment of the “observed impacts, vulnerability and adaptation” to climate change.
|Confidence level||Observed phenomenon resulting from climate change|
|Very High||Differences in vulnerability and exposure arise from non-climatic factors and from multidimensional inequalities often produced by uneven development processes|
|Very High||Impacts from recent climate-related extremes, such as heat waves, droughts, floods, cyclones, and wildfires, reveal significant vulnerability and exposure of some ecosystems and many human systems to current climate variability|
|High||Adaptation and mitigation choices in the near-term will affect the risks of climate change throughout the 21st century|
|High||Adaptation experience is accumulating across regions in the public and private sector and within communities|
|High||Adaptation is becoming embedded in some planning processes, with more limited implementation of responses|
|High||Based on many studies covering a wide range of regions and crops, negative impacts of climate change on crop yields have been more common than positive impacts|
|High||Climate-related hazards exacerbate other stressors, often with negative outcomes for livelihoods, especially for people living in poverty|
|High||Many terrestrial, freshwater, and marine species have shifted their geographic ranges, seasonal activities, migration patterns, abundances, and species interactions in response to ongoing climate change|
|High||Responding to climate-related risks involves decision-making in a changing world, with continuing uncertainty about the severity and timing of climate-change impacts and with limits to the effectiveness of adaptation|
|High||Uncertainties about future vulnerability, exposure, and responses of interlinked human and natural systems are large|
|Medium||In many regions, changing precipitation or melting snow and ice are altering hydrological systems, affecting water resources in terms of quantity and quality|
The summary then presents the following eight “key risks” that the IPCC feels “are identified with high confidence, span sectors and regions.”
The risks are:
- Risk of death, injury, ill-health, or disrupted livelihoods in low-lying coastal zones and small island developing states and other small islands, due to storm surges, coastal flooding, and sea-level rise
- Risk of severe ill-health and disrupted livelihoods for large urban populations due to inland flooding in some regions.
- Systemic risks due to extreme weather events leading to breakdown of infrastructure networks and critical services such as electricity, water supply, and health and emergency services
- Risk of mortality and morbidity during periods of extreme heat, particularly for vulnerable urban populations and those working outdoors in urban or rural areas.
- Risk of food insecurity and the breakdown of food systems linked to warming, drought, flooding, and precipitation variability and extremes, particularly for poorer populations in urban and rural settings.
- Risk of loss of rural livelihoods and income due to insufficient access to drinking and irrigation water and reduced agricultural productivity, particularly for farmers and pastoralists with minimal capital in semi-arid regions.
- Risk of loss of marine and coastal ecosystems, biodiversity, and the ecosystem goods, functions, and services they provide for coastal livelihoods, especially for fishing communities in the tropics and the Arctic.
- Risk of loss of terrestrial and inland water ecosystems, biodiversity, and the ecosystem goods, functions, and services they provide for livelihoods.
The summary eventually considers “overlapping approaches” to “adaptation” that will help humanity to ameliorate climate change. Many types of adaptation are suggested, ranging from better land planning laws to the creation of “catastrophe bonds”.
The summary also offers Reg readers a few clues about how climate change might impact them in their backyards. Here's a few selections from the summary's report of climate change impacts:
- Shift from cold-related mortality to heat-related mortality in England & Wales Improved crop productivity in Northern Europe, thanks in part to technology and a little due to climate change
- Invasive plant and fish species to do better in Europe
- Less water in spring snowpack across North America More wildlife in subantarctic forests of North America North American fish to migrate further north
- More coral bleaching on Australia's Great Barrier reef New Zealand's glaciers to retreat and snow depth at Australia's already-mediocre ski resorts to lessen
And here's the worst Australian impact of all: wine grapes look likely to ripen later in the year. Whatever else you think of this report or of climate change in general, everyone can identify with slower maturation of wine grapes as an issue worth tackling. ®