The World Meteorological Organisation co-ordinated a report showing climate change and its impacts between 2015 and 2019, showing it was the hottest five-year period on record.

By Ian Horswill

Posted on September 23, 2019

For the past decade a visit to my general practitioner has always included the advice of “go for a swim in the ocean”. But all that sodium, chloride, sulphate, magnesium and calcium is being reduced by the amount of acid in the oceans due to climate change, according to a synthesis report published on the eve of the United Nations Secretary-General’s Climate Action Summit.

The World Meteorological Organisation (WMO) co-ordinated a report showing climate change and its impacts between 2015 and 2019, showing it was the hottest five-year period on record.

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The report stated that the observed rate of global mean sea-level rise accelerated from 3.04 millimetres per year (mm/yr) during the period 1997–2006 to approximately 4mm/yr during the period 2007–2016.

“This is due to the increased rate of ocean warming and melting of the Greenland and West Antarctica ice sheets. There has been an overall increase of 26% in ocean acidity since the beginning of the industrial era, said the WMO in a press release.

“Arctic summer sea-ice extent has declined at a rate of approximately 12% per decade during 1979-2018. The four lowest values for winter sea-ice extent occurred between 2015 and 2019.

“Overall, the amount of ice lost annually from the Antarctic ice sheet increased at least six-fold between 1979 and 2017. Glacier mass loss for 2015-2019 is the highest for any five-year period on record.”

The report, United in Science, advocates the urgency of fundamental socio-economic transformation in key sectors such as land use and energy in order to avert dangerous global temperature increase with potentially irreversible impacts.

“The Report provides a unified assessment of the state of our Earth system under the increasing influence of anthropogenic climate change, of humanity’s response thus far and of the far-reaching changes that science projects for our global climate in the future. The scientific data and findings presented in the report represent the very latest authoritative information on these topics,” said the Science Advisory Group to the UN Secretary-General’s Climate Action Summit.

“It highlights the urgent need for the development of concrete actions that halt the worst effects of climate change.”

The Science Advisory Group is co-chaired by WMO Secretary-General Petteri Taalas and Leena Srivastava, former Vice Chancellor of TERI School of Advanced Studies, a not-for-profit, independent research institute.

The report stated that levels of the main long-lived greenhouse gases, carbon dioxide (CO2), methane (CH4)) and nitrous oxide (N2O), have reached new highs.

“The last time Earth’s atmosphere contained 400 parts per million CO2 was about 3-5 million years ago, when global mean surface temperatures were 2-3°C warmer than today, ice sheets in Greenland and West Antarctica melted, parts of East Antarctica ice had retreated, all causing global see level rise of 10-20m compared with today,” WMO stated.

“In 2018, global CO2 concentration was 407.8 parts per million (ppm), 2.2 ppm higher than 2017. Preliminary data from a subset of greenhouse gas monitoring sites for 2019 indicate that CO2 concentrations are on track to reach or even exceed 410 parts per million (ppm) by the end of 2019.

“In 2017, globally averaged atmospheric concentrations of CO2 were 405.6 ±0.1 ppm, CH4) at 1859 ±2 parts per billion (ppb) and N2O at 329.9 ±0.1 ppb. These values constitute, respectively, 146%, 257% and 122% of pre-industrial levels (pre-1750).

“The growth rate of CO2 averaged over three consecutive decades (1985–1995, 1995–2005 and 2005–2015) increased from 1.42 ppm/yr to 1.86 ppm/yr and to 2.06 ppm/yr.”

Iceberg in the Antartic. Photo: Danting Zhu / Unsplash

International Science Council President Daya Reddy said the findings presented in the report “convey with clarity and authority the stark reality of an existential crisis; one that is of our own making.”

“The evidence of the anthropogenic nature of this crisis is incontrovertible. We are confronted on a daily basis with its immediacy, as experienced by communities around the world, and most severely by those that already grapple with extremes of poverty and inequality”, he said.

Dr Flavia Schlegel, the ISC’s Special Envoy for Science in Global Policy, said: “This landmark multi-partner report says loud and clear that our planet is warming, it’s caused by humans, the science is certain, and while it presents an existential crisis, together we can fix it if we unite behind the science”.

“This report shows that the science is non-negotiable and governments need to act now.”