Opponents of climate change action

Is climate change real?

There is clear evidence that our climate is changing, largely due to greenhouse gases caused by human activities. When scientists talk about climate change they mean warming of the climate system as a whole, which includes the atmosphere, the oceans, and the cryosphere (ice, snow and frozen ground). The observational evidence clearly indicates that the climate system is continuing to warm, including warming oceans and melting snow and ice, both of which contribute to rising sea levels.

The Fourth Assessment Report, produced by the Intergovernmental Panel on Climate Change (IPCC) in 2007, states that global warming is 'unequivocal' and that 'most of the observed increase in globally-averaged temperatures since the mid-20th century is very likely due to the observed increase in greenhouse gas concentrations'.

In other words, there is overwhelming evidence for human-made global warming.

Climate change is not just about global warming. The science indicates that the climate will be altered in many other ways. For example, there will be changes in rainfall patterns and ocean currents, changes to the intensity and frequency of extreme events such as storms, droughts and floods, rising global sea level and ocean acidification.

Has there been a decade and a half with no 'statistically significant' global warming?

Statistically significant trends cannot be determined from 15 years of data. The IPCC specifies that 25 years is the minimum period required to determine a statistically significant trend. Even so, the linear trend for the last 15 years has been one of warming.

The current observed global temperature changes are consistent with the climatic warming trend of 0.2 degrees Celsius per decade predicted by the IPCC. Using NASA data, even the 11-year period (cited by some commentators as evidence against warming) starting with the warm 1998 and ending with the cooler 2008, still shows a warming trend of 0.11 degrees Celsius per decade.

The World Meteorological Organization has found that 2000-2009 was the world's warmest decade on record, warmer than the 1990s which in turn was warmer than the 1980s. In Australia, the Bureau of Meteorology has found each decade since the 1940s has been warmer than the preceding decade. The Earth has warmed by around 0.74 degrees Celsius from 1906-2005. This is a statistically significant climatic change.

Are warming rates below the Intergovernmental Panel on Climate Change (IPCC) projections?

No. Carbon dioxide levels, global average surface air temperature and sea-level change are all tracking within IPCC projections.

Are the IPCC findings based on a show of hands among political representatives?

No. The Fourth Assessment Report of the IPCC provides a rigorous assessment of the published and peer-reviewed research on climate change and was compiled by 1,250 expert authors from over 130 countries.

The Report is based on a range of scientific evidence for climate change including observed increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.

All IPCC reports are subject to extensive expert and government review. The role of governments in the review process is to assist in ensuring the reports comprehensively cover scientific sources and are relevant to the needs of decision makers.

Has a natural reduction in cloud cover caused the warming from the mid 1980s rather than CO2?

The available evidence, as presented in the IPCC Fourth Assessment Report, indicates that greenhouse gases emitted by human activities have contributed more to warming over the last fifty years than any natural source. Studies have been unable to find any natural causes that explain the scale of observed warming.

Does climate change represent a market failure?

A 'market failure' in this context refers to the fact that, until now, no one has had to pay for the damage inflicted on our global climate from carbon pollution.

If polluters do not pay directly for the cost of their pollution, that cost is passed indirectly onto everyone else (for example, in the form of poor air quality or in this case, global warming). That is why the Government has introduced a mechanism that requires the country's biggest polluters to pay for each tonne of pollution they release into the atmosphere. This will encourage them to move towards low-emissions alternatives overtime.

Is the cost of reducing emissions (mitigation) worth it? Is waiting and adapting more cost-effective?

Even small changes in global average temperature have significant and costly impacts. Regardless of future efforts to reduce emissions, the level of greenhouse gases already in the atmosphere means that some impacts cannot be avoided. Today we are already beginning to feel the economic and environmental costs of inaction on climate change.

The Government's support of global action to reduce emissions is based on the science that indicates that stabilising greenhouse gas concentrations in the atmosphere at 450 parts per million (ppm) or lower will reduce the risks of severe climate change, and support our aim of limiting the average global temperature increase to no more than 2 degrees Celsius. At a 2 degree temperature rise we will certainly need to adapt.

Without effective global action on climate change, temperatures in Australia could rise by around 5 degrees Celsius by the end of the century. The results would be catastrophic.

Food production from our farms would decline. We would experience more bushfires and severe weather events that threaten the livelihoods of our communities. Human health would be at risk from the spread of disease. And the Great Barrier Reef is under serious threat as increasing sea temperatures cause coral bleaching and as the ocean acidifies. Some of these impacts we simply cannot adapt to.

As set out in a number of authoritative resources (such as the Stern Review and the Garnaut Review), the costs of inaction far outweigh the costs of action now. We need to reduce emissions so that our aim of limiting average global temperature increase to no more than 2 degrees remains achievable. The more there is delay in real action to substantially reduce greenhouse gas emissions, the harder it becomes to achieve this goal.