An Taisce is calling on the world’s leaders to agree and enforce a cap on global Cumulative Total Emissions at the UN summit in New York next week

Climate science in now clear that Cumulative Total Emissions (CTE) is the essential measure that must be used when calculating the needed reductions - not delayed percentage targets as presently used. Cumulative Total Emissions (CTE) are critical to climate action that ensures local and national efforts are not undermined anywhere now or in the future.

The findings of the 5th Assessment Report of the IPCC have changed the climate equation. There is now an overwhelming scientific consensus that:

  • The added greenhouse gases (GHGs) generated by human activity are causing abrupt global warming, by trapping ever more incoming solar energy.

  • Carbon dioxide (CO₂), the GHG from burning fossil fuels, accumulates in the atmosphere.

  • There is a direct linear connection between the total amount of CO₂ emitted and the resulting increase in the global average temperature.

Professor Barry McMullin of An Taisce’s Climate Change Committee stated: “Cumulative total emissions (CTE) are the global ‘thermostat’. We must now agree an absolute limit on how much further we will turn this thermostat up - which means a limit on our total remaining cumulative emissions - if we are to avoid severe or even catastrophic impacts. These include drastic food, water and energy shortages, sea level rise, major population movements, widespread species extinction and ecosystem collapse. Concerted action now will reduce the risk.”

All sectors of society and all nations must now declare how much of this dwindling remaining CTE capacity they each claim - based on a calculation. Given historic emissions and high consumption patterns, the wealthy developed countries must accept higher and more immediate burdens of reduction responsibility and cost. Affordable climate adaptation will be possible only if the least cost option, urgent mitigation, is achieved quickly.

For further information, please call:
Prof. Barry McMullin, Chair, An Taisce Climate Committee, phone: 087-913-0513
Charles Stanley-Smith, Communications, An Taisce Tel: +353 87 2411995
email: [email protected]
An Taisce The National Trust for Ireland


  1. An Taisce’s Position paper

  2. An Taisce’s Briefing Document

  3. At Copenhagen in 2009 the international community agreed that it is essential to limit the increase in average global temperature to a maximum of 2ºC (above pre-industrial levels) to avoid dangerous global climate change. It was agreed that equity between nations and with future generations is critical to action.

  4. Scientifically, the 2ºC limit directly implies an absolute global limit to CTE, meaning all future, human-caused emissions. Global GHG emissions continue to accelerate annually adding ever more to the accumulating atmospheric stock of CTE.

  5. The 4ºC rise currently projected implies high severity global impacts coming this century due to investments being made now. Limiting warming to 2ºC requires urgent and radical decarbonisation with all nations specifying their portion of the global CTE or else the 2ºC limit will be exhausted within 25 years.

  6. EU policy calls for steady, per cent decreases in annual emissions over a time period. However, limiting the rate in a stated end year is not sufficient as it is the total sum of emissions that counts and must be counted.

  7. To achieve fair, effective and transparent action, explicit national CTE targets and continuous efforts are required to ensure meeting the global CTE target. Excess emissions unfairly steal from the total carbon budget increasing future impacts. The future carbon budget is locked in by policy and carbon commitments being made now.