Warming is 'unequivocal' confirms IPCC

30th September 2013


Related Topics

Related tags

  • Mitigation

Author

IEMA

Substantial and sustained reductions in greenhouse-gas (GHG) emissions are required to limit the escalating warming of the planet, the authors of the latest report from the Intergovernmental Panel on Climate Change (IPCC) conclude

Thomas Stocker, co-chair of working group I, which produced the report, said: “As a result of our past, present and expected future emissions of carbon, we are [locked into] climate change, and the effects will persist for many centuries even if emissions stop. Continued emissions will cause further warming and changes in all components of the climate system.”

The report is the first of four that will be published by the IPCC over the next year as part its fifth assessment of climate science and is based on 9,200 peer-reviewed papers. It describes the warming of the Earth’s climate system as “unequivocal”, and says many of the observed changes are unprecedented over millennia.

Human influence on the climate system is clear, with human activities extremely likely to have been the dominant cause of the observed warming since the mid-20th century, conclude the scientists. They confirm that each of the past three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850, with concentrations of CO2 increasing by 40% since pre-industrial times, primarily from fossil fuel emissions.

The document includes projections of climate change based on a new set of four scenarios of future GHG concentrations. Projections for changes in global surface temperature by the end of the century range from 0.3°C to 4.8°C compared with 1985–2003 levels. The report notes that warming over land will be greater than over the ocean.

Governments have pledged to limit temperature rise to 2°C to avoid potentially dangerous consequences, and the report makes it clear that staying below that threshold will mean leaving large amounts of fossil fuels in the ground. To stay below 2°C total global emissions must not exceed 1,000 gigatonnes of carbon (GtC), warns the IPCC. By 2011, 531 GtC had already been emitted.

“Without immediate reductions in global emissions of GHGs, the world will not be able to achieve the political target of limiting the increase in global mean surface temperatures to 2°C, but rather we are likely to see an increase of 3°C–5°C,” commented Professor Robert Watson, director of strategic development at the Tyndall Centre for Climate Change Research. “Time to act is running out if we are to take the threat of human-induced climate change seriously.”

Headlines from the IPCC report

  • Each of the past three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850.
  • Levels of greenhouse gases in the atmosphere are unprecedented in the past 800,000 years.
  • Concentrations of CO2 have risen by 40% since pre-industrial times, primarily from fossil fuel emissions.
  • In the northern hemisphere, 1983–2012 is likely to have been the warmest 30-year period in the past 1,400 years.
  • Human influence has been detected in warming of the atmosphere and the ocean; in changes in the global water cycle; in reductions in snow and ice; and in global sea level rise.
  • Ocean warming accounts for over 90% of the energy accumulated in the climate system in 1971–2010.
  • The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia. Sea level rise will be between 26cm and 82cm by 2100.

Subscribe

Subscribe to IEMA's newsletters to receive timely articles, expert opinions, event announcements, and much more, directly in your inbox.


Transform articles

Facing the climate emergency challenge in local government

It’s well recognised that the public sector has the opportunity to work towards a national net-zero landscape that goes well beyond improving on its own performance; it can also influence through procurement and can direct through policy.

19th March 2024

Read more

The UK government’s carbon capture, usage and storage (CCUS) strategy is based on optimistic techno-economic assumptions that are now outdated, Carbon Tracker has warned.

13th March 2024

Read more

The UK’s new biodiversity net gain (BNG) requirements could create 15,000 hectares of woodlands, heath, grasslands, and wetlands and absorb 650,000 tonnes of carbon each year.

13th March 2024

Read more

The UK government’s latest Public Attitudes Tracker has found broad support for efforts to tackle climate change, although there are significant concerns that bills will rise.

13th March 2024

Read more

Multinational corporations are undermining their net-zero commitments with excessive air travel and no plans to reduce ‘the low hanging fruit’ of carbon footprints, a study by Transport & Environment has found.

13th March 2024

Read more

The UK government’s climate adaptation plans are ‘inadequate’ and falling ‘far short’ of what is required, the Climate Change Committee (CCC) has warned today.

13th March 2024

Read more

Large businesses across the world are avoiding climate action due to fear they will be called out for getting their work wrong, according to a new Carbon Trust report.

29th February 2024

Read more

A thought-provoking discussion on how storytelling can change the world took place in Central London last night, alongside an exclusive sneak preview of an upcoming IEMA film series.

29th February 2024

Read more

Media enquires

Looking for an expert to speak at an event or comment on an item in the news?

Find an expert

IEMA Cookie Notice

Clicking the ‘Accept all’ button means you are accepting analytics and third-party cookies. Our website uses necessary cookies which are required in order to make our website work. In addition to these, we use analytics and third-party cookies to optimise site functionality and give you the best possible experience. To control which cookies are set, click ‘Settings’. To learn more about cookies, how we use them on our website and how to change your cookie settings please view our cookie policy.

Manage cookie settings

Our use of cookies

You can learn more detailed information in our cookie policy.

Some cookies are essential, but non-essential cookies help us to improve the experience on our site by providing insights into how the site is being used. To maintain privacy management, this relies on cookie identifiers. Resetting or deleting your browser cookies will reset these preferences.

Essential cookies

These are cookies that are required for the operation of our website. They include, for example, cookies that enable you to log into secure areas of our website.

Analytics cookies

These cookies allow us to recognise and count the number of visitors to our website and to see how visitors move around our website when they are using it. This helps us to improve the way our website works.

Advertising cookies

These cookies allow us to tailor advertising to you based on your interests. If you do not accept these cookies, you will still see adverts, but these will be more generic.

Save and close