The IPCC needs to change, but the science remains sound

One criticism often aimed at the IPCC is that it is inflexible and unable to conduct rapid response assessments of new evidence due to the requirements of two rounds of peer review involving experts and governments. One solution to this weakness is to complement, not replace, the IPCC by developing a “peer-reviewed” Wikipedia that can continually update the evidence and synthesise the findings and note where the new evidence strengthens, modifies, or undermines previous conclusions.

In my opinion, there is no doubt that the evidence for human-induced climate change is irrefutable. The world’s leading scientists, many of whom have participated in the IPCC, overwhelmingly agree that what we’re experiencing cannot be attributed to natural variation in the climate over time, but is due to human activities. And they also agree that if we do not act, climate change will continue apace with increasing droughts, floods, and rising seas, leading to major damaging impacts to the natural world (loss of species and critical ecosystem services) and society (displaced human populations).

There is no doubt that the atmospheric concentration of greenhouse gases has increased significantly over the past 150 years primarily due to human activities. These gases are radiatively active and absorb and trap outgoing infrared radiation from the Earth’s surface and hence, based on simple physics, the Earth’s atmosphere must respond by warming. The only issue is by how much and when.

The IPCC concluded that the global temperature data and analyses are robust, with evidence of increasingly variable and extreme temperatures, coupled with increasingly severe weather events, heat waves, floods, and droughts. While a number of scientists argue that some of the land temperature data is contaminated and unreliable because of the urban heat-island effect and movement of observational sites, ocean data - as well balloon and satellite data - also show an increasingly warmer world. These data sets are clearly free from any potential contamination from any urban heat island effect.

In addition, the evidence for a changing climate over the past 100 years also comes from observed changes in retreating mountain glaciers throughout most of the world, a decline in the extent and thickness of Arctic sea ice, melting of the Greenland ice sheet, changes in precipitation patterns, and changes in vegetation and the behaviour of wildlife. Yet despite this accumulating evidence, the challenges of the sceptics must be fully addressed.

The key question is the cause of the observed changes in temperature. The IPCC concluded that it is more than 90 per cent certain that most of the observed changes over the past 50 to 60 years are due to human activities and that the changes cannot be explained by known natural phenomena.

Future increases in greenhouse gas concentrations are projected to be accompanied by increased climate variability and more extreme climatic events, leading in general to adverse impacts on agriculture, water quantity and quality, coastal erosion, loss of biodiversity, and degradation of ecosystem services. Developing countries will be the most vulnerable. Therefore, it is clear that climate change is not only an environmental issue, but a development and security issue.

All major emitters of carbon dioxide and other greenhouse gases need to rapidly and cost-effectively transition to a low-carbon economy, in both the production and use of energy and the management of forests and agricultural lands. In order to ensure food, water, and human security, and to protect the world’s biodiversity, the goal should be to limit the global average temperature rise to 2 degrees C (3.6 degrees F) above pre-industrial levels. This will require a peak of global emissions of all greenhouse gases by around 2015, and at least a 50 per cent reduction in global emissions by 2050, relative to 1990. Without concerted action now, the world will be faced with temperature increases far in excess of 2 degrees C, with unthinkable impacts.

An equitable and substantive post-Kyoto agreement is essential if the target of 2 degrees C is to be realised. Industrialised countries must demonstrate leadership, and provide developing countries with technical and financial assistance to reduce their greenhouse gas emissions while they address the critical issues of poverty and hunger.

Given the limited success at Copenhagen, 2010 is a critical year for the world’s political leaders to unite in the fight against climate change. Strong and visionary political leadership will be essential. We must not allow the sceptics to use the incident at the University of East Anglia or the mistakes in the IPCC report to distract us or derail the political will to safeguard the planet.