As discussed in the Future Climate Forecast section, many scientists from around the world have participated in a project for the United Nations, to work out what the global temperature is likely to be by 2100.

The outcomes depend entirely on what we decide to do in the next few decades.

FIGURE 1 : Global Warming Impacts

Food

Water

Ecosystems

Extreme weather events

Risk of rapid climate change and major irreversible impacts

"Melting of glaciers and ice sheets also contributes to sea-level rise. Vast quantities of ice are locked away in the ice sheets of West Antarctica and Greenland, collectively equivalent to approximately 12 meters of sea-level rise. Destabilisation or collapse of these ice sheets would lead to centuries of irreversible sea-level rise and coastal inundation around the world." CSIRO p.31

In April 2006, a report titled, "The Business Case for Early Action" was released by the Australian Roundtable on Climate Change. The Roundtable was formed by some of Australia’s largest and most respected businesses; BP Australia, Insurance Australia Group, Origin Energy, Swiss Re, Visy Industries and the Westpac Bank, as well as the Australian Conservation Foundation.

The Roundtable commissioned the CSIRO (Commonwealth Scientific and Industrial Research Organisation) to "to quantify climate impacts on Australia".

The opening statement of the report states:

TABLE 1: Impacts on Australia from global temperature rises (above current levels)

CSIRO has identified that certain Australian systems are highly vulnerable to climate change. Loss of unique natural environments, increasingly scarce water supplies and more frequent extreme weather events will have significant implications for a number of important Australian industry sectors and the economy.

The report states that, "Over the next century and beyond, climate change will result in a broad range of consequences for most regions, including Australia".

The following paragraphs are either quoted, or paraphrased from the Roundtable report (p.23-31). Paraphrasing is used to replace scientific language with simple English, in order to make it easier to understand.

A number of Australia’s ecosystems are vulnerable to changes in temperature and rainfall. Therefore, significant negative consequences from climate change are projected, even for relatively small shifts in climate conditions.

"Recent studies indicate that globally, natural ecosystems are already responding to climate change. 56 For some species, these responses appear to part of coping strategies, for others adverse effects including localized population extinctions have been observed."

"The Great Barrier Reef, a UNESCO World Heritage area, is particularly vulnerable to climate change."

"…considerable losses or contractions of species associated with coral communities are projected for a further warming of only 1°C."

With large increases in warming, negative effects for certain groups of species are expected to become progressively worse.

"Annual damage to the Great Barrier Reef increases to the point of catastrophic failure, snow cover and duration decreases substantially, and species are lost".

The cropping, forestry, and livestock sectors are influenced by changes in climatic conditions and also by increases in atmospheric CO2.

Average changes will be far less important in this context than more extreme events, which can have catastrophic impact on the economic viability of long-rotation crops. Large areas of Australian plantations are "on the edge" in terms of drought risk. Fire frequency and severity is a major risk for plantations. A number of key plantation pests are favoured by warm summer conditions or tree drought stress.

Temperature increases will stress livestock, leading to reductions in milk production even for warming of just 1°C. Decreases in precipitation will lower the quality of native pasture land, resulting in reduced productivity of native pasture land for grazing livestock. Meanwhile, like crop agriculture, pests such as ticks may reduce cattle productivity.

"Water resources are increasingly a core issue for both the developed and, particularly the developing world due limited resources and a growing global population."

"Australia is currently facing extensive water resource challenges, particularly in the southwest, where current precipitation, run-off, and stream flows have dropped to levels well below long-term average. Water storage in reservoirs is also well below capacity throughout much of West and South Australia, Victoria, and Queensland."

"Inflows to reservoirs in NSW have been projected to decrease by up to 15% for just a 1°C increase in temperature. Generally, such decreases grow in magnitude with higher magnitudes of warming as demonstrated by impact assessments for a range of reservoirs across NSW, Victoria, and South Australia."

TABLE 2 : Projected impacts to Australian Water Resources

"…extreme weather events such as severe storms, wind, and flooding also contribute to injury and mortality on an annual basis."

"In addition to the direct health effects of climate, there are a range of indirect consequences. Higher temperatures have been linked with higher levels of tropospheric ozone, particularly in urban areas, which can induce respiratory and cardiovascular illness and death."

"Climate change could cause large increases in flooding deaths and injuries, depending upon future changes in precipitation extremes. Climate change could cause the range of mosquito vectors for dengue and malaria to expand southward."

TABLE 3

"Many aspects of human settlements where people live, work, and play are exposed to the climate, prompting concern about the potential impacts of climate change."

"Australia’s coastal zone is of particular concern, due to its thousands of kilometres of coastline and the concentration of much of Australia’s population, commerce, and industry in the coastal zone. Climate modelling has suggested that storm winds, including those associated with tropical cyclones, may become more intense with a warming of 1–2°C."

"This combined with sea-level rise would result in higher storm surge during storm events and a greater area flooded. In addition, higher wind speeds would increase storm damages as they tend to increase with the square of wind speed."

"Sea-level rise and storm events also contribute to coastal inundation and beach erosion, which may affect popular tourism and recreation areas. At higher levels of warming, coastal impacts become more severe with higher storm winds and sea levels."

"Extreme events tend to inflict large environmental and economic costs"

Globally, the World Meteorological Organization has claimed that extreme events are on the rise as a result of changes in the climate system, caused by human activity. Also, "climate models indicate the potential for increases in extremes of temperature, precipitation, droughts, storms, and floods".

"Australia is prone to bushfires, cyclones, hail, storms and flood, all of which are expected to increase in frequency and/or intensity due to climate change." ARCC p.14

TABLE 4 : Climate Change and Extreme Weather Events

"Steady growth in Australia’s population combined with the concentration of Australia’s population within 50 km of the coast has exposed greater numbers of people, wealth and infrastructure to extreme weather events. These socioeconomic trends are projected to continue for at least the next half century, and thus Australia’s vulnerability to extreme events will continue to increase."

A large-scale singularity is where "systems switch from one state to another, could cause a broad range of direct and indirect consequences to many regions of the world, including Australia."

Corel Reefs; "Perhaps the singularity of most immediate relevance to Australia is the of coral reef ecosystems, which appear to switch quite rapidly from being healthy to being stressed, bleached, or eliminated."

With the temperature, rainfall, water availability and humidity changing in the future, the living conditions for insects will also change. The ideal habitat for many insects and pest will change and as they spread into new areas, they take with them diseases.

Below is a projected scenario for the spread of Malaria. What is interesting is that not only do existing habitats extend, but entirely new areas are exposed, such as Australia.

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With climate conditions changing in the future, due to increased concentrations of Carbon Dioxide in the atmosphere, conditions for pests also change. The primary Malaria agent, the falciparum malaria parasite, will be able to spread into new areas, as displayed in this map, by 2050 using the Hadley CM2 high scenario. Other areas, not displayed in the map, will be uninhabitable by the parasite, and thus free of the pest.

The Australian Roundtable on Climate Change built on the scientific report developed by the CSIRO. The Roundtable commissioned the Allen Consulting Group to conduct economic modelling on the cost to Australia to reduce emissions by 60% by 2050 based on 2000 levels.

One of the remarks in the report comments about the target, "Some will think that this target is impossible given the magnitude of the task, but this is not the case."

The research by the Allen group looked at two scenarios:-

An early action: a 60% reduction in Australia’s emissions by 2050 starting with action in 2013

Delayed action: a 60% reduction in Australia’s emissions by 2050 starting with action in 2022

"Acting early to reduce emissions may not only avoid damage, but can buy time to adapt to a harsher and more varied climate." ARCC p.20

"By acting early, Australia will retain the flexibility to implement policies that will limit disruptive shocks to the economy. Importantly, the research also found that the longer we delay taking action, the more expensive it becomes to implement the reductions needed to avoid dangerous climate change. Minimising policy uncertainty around near and long-term emission limits is very important to ensure timely investment in the infrastructure required to support the Australian economy and maintain our international competitiveness." ARCC p.20

Other countries have adopted the 60% reduction target as well;

"The UK Prime Minister Tony Blair has adopted a target of 60% reduction by 2050 following advice from the Royal Commission on Environmental Pollution in the United Kingdom. This is consistent with widely disseminated and well known long–term target analysis work from Sweden, the European Union and the United States10,11."

The Australian Roundtable on Climate Change made a number of recommendations for what the Australian government should do.