The response to climate change

The response to climate change

(Image: IPCC)

The Intergovernmental Panel on Climate Change : IPCC

  • In 1988 the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) established the IPCC to provide governments and policymakers around the world with regular scientific assessments on what’s known about climate change.
  • As our understanding of climate change grows with new research, new reports are produced every few years.
  • The reports include scenarios: what our futures might be like depending on how much more warming we cause.

The process

Once it became clear that the world’s climate was changing, it was also evident that every aspect of life on Earth would be affected. The IPCC was formed to gather research from around the world, evaluate it, and use it to make predications about the impacts, with the objective of  ‘stablising greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic (human-induced) interference with the climate system’.

By gathering research from across all sectors, the IPCC is also able to see where there are gaps in knowledge, which in turn to direct research.

Each of the five Assessment Reports that have been published since 1988 runs into several million words, are in several parts, and were collated over four to five years by scientists and researchers nominated by their respective governments (Fig. 1). This process ensures that:

  1. All member nations are represented
  2. There is time to include all relevant material
  3. A consensus is reached by all nations prior to each Assessment Report being released

Thousands of scientists and other experts around the world volunteer their time to write and review the draft reports. As these are long and technical to ensure the research is robust and comprehensive, there is also a summary report for policymakers. Delegates from all participating governmentsaround 120 including New Zealandcheck the summary report line-by-line, and all countries have to agree on the wording before the final report is published.

The Sixth Assessment Report now underway is due in 2022.

Fig. 1: The process or ‘cycle’ of each of the six reports. The cycle of the sixth report is now underway and due to be completed in 2022. (Image: IPCC)

Criticisms of being too conservative

There were some assumptions in earlier reports that have not (so far) come to pass; primarily

  • Once governments knew the problems that climate change would bring, they would act quickly to replace fossil fuels withe renewable energy sources. This is slowly happening, but not anywhere fast enough, and not by all governments. 
  • Technologies would be invented and installed to remove excess greenhouse gasses from the atmosphere. This technology exists, but is not being deployed on a large enough scale.

There are two other key criticisms:

  • Some nations have (and continue) to reject aspects of the science and implications of climate change, so they insist on language in the summary reports that downplay the scale and urgency of the problems that have been cleary spelled out in the technical reports.
  • It takes time, sometimes years to gather robust evidence, write research papers, and have that research published. Some research included in the IPCC may be more than a decade old, so by the time IPCC reports are released, information that has led to forecasts, and conclusions may already be superseded. For example, the 2001 Third Assessment Report included predictions about sea level rise and temperatures, with the ‘worst case’ scenario regarded as least likely. On the eve of the Fourth Assessment Report in 2007, a study was published showing the temperatures were at the top end of the worst predictions, and sea levels were rising much faster (Fig. 2).

Most recent reports

Earlier reports have been now been superseded by the 2013/2014  Fifth Assessment Report which was used as the basis of the Paris Agreement to keep global temperatures under 2.0°C.

Interim reports that focus in specific issues take into account more recent observations and research:

 

Fig. 2 : Changes in key global climate parameters since 1973. Top: Monthly carbon dioxide concentrations; different colours are from different measuring stations. Middle: annual global-mean surface temperature; the grey area are IPCC projections). Bottom: sea-level data based on tide gauges and satellite altimeter; the grey area are IPCC projections.

References and further reading