Dangerous levels of climate change possible in this lifetime

By Tierney Smith

ariel image of flooding in Pakistan

Flooding in Dadu District Pakistan (source: UN/Amjad Jamal)

People living today will see dangerous levels of climate related impacts including flooding, sea levels rising and drought unless quick and steep emissions reductions are implemented, according to two reports published in Nature Climate Change.

One study by academics at the Universities of Oxford and Reading and the Met Office’s Hadley Centre says substantial reductions in greenhouse gases will be needed in coming decades to prevent dangerous climate change in the lifetime of those living today.

While the research found that under lower emissions scenarios, the crossing of the two degree threshold could be delayed by several decades, in the higher scenarios the threshold could be crossed by 2060.

It also found that due to regional scales of temperature rise, large parts of Eurasia, North Africa and Canada could exceed two degrees as early as 2040, if emissions continue to increase.

By drawing attention to the rates of climate change, the study aims to shift emphasis towards understanding how early adaptation measures – which often take a long time to implement – need to be considered.

2°C has been hailed as the maximum limit of temperature rise to avoid dangerous climate change and impacts including increased flooding, droughts and rising seas levels.

At the UN conference in Copenhagen in 2009, industrialised countries set out a vision for deep cuts in global greenhouse gas emission to hold the increase to below this limit.

In the lead up to next UN climate conference in Durban, next month, many countries and experts are calling for a tougher ambition. UNFCCC Chief, Christiana Figueres said: “We will actually have to raise our ambition to a 1.5C as a maximum temperature rise.”

To meet either of these aims deep and sharp cuts in global greenhouse gas emission are needed, says the report.

In a second report, also published in Nature Climate Change by academics from ETH Zurich University, the Potsdam Institute and the Hadley Centre results found that keeping temperature rises within the two degree bracket would be difficult.

The study used a large set of published emissions scenarios to track greenhouse gas concentrations related to limiting 2°C and found it would be unlikely in the absence of strongly negative emissions.

The set of scenarios with a ‘likely’ – greater than 66 per cent – chance of staying below 2°C saw emissions peak between 2010 and 2020 and fall to a median level of 44Gt of CO2 equivalent by 2020.

None of the scenarios – even those with the most stringent mitigation policies – would see global temperatures remain within 1.5°C of pre industrialised levels, although some scenarios within the study saw warming decline again to below this temperature by 2100.

The second report warns: “Without a firm commitment to put in place the mechanism to enable an early global emissions peak followed by steep reduction thereafter, there are significant risks that the 2°C target endorsed by so many nations is already slipping out of reach.”


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