WMO Statement on the State of the Global Climate in 2018
Foreword
This publication marks the twenty-fifth anniversary of the WMO Statement on the State of the Global Climate, which was first issued in 1994. The 2019 edition treating data for 2018 marks sustained international efforts dedicated to reporting on, analysing and understanding the year-to-year variations and long-term trends of a changing climate.
Substantial knowledge has been produced and delivered annually during this period to inform WMO Member States, the United Nations system and decision-makers about the status of the climate system. It complements the Intergovernmental Panel on Climate Change (IPCC) five-to-seven year reporting cycle in producing updated information for the United Nations Framework Convention for Climate Change and other climate-related policy frameworks.
Since the Statement was first published, climate science has achieved an unprecedented degree of robustness, providing authoritative evidence of global temperature increase and associated features such as sea-level rise, shrinking sea ice, glacier mass loss and extreme events linked to increasing temperatures, such as heatwaves. There are still areas that need more observations and research, including assessing the contribution of climate change to the behaviour of extreme events and to ocean currents and atmospheric jet streams that can induce extreme cold spells in some places and mild conditions in others.
Key findings of this Statement include the striking consecutive record warming recorded from 2015 through 2018, the continuous upward trend in the atmospheric concentration of the major greenhouse gases, the increasing rate of sea-level rise and the loss of sea ice in both northern and southern polar regions.The understanding of the linkage between the observed climate variability and change and associated impact on societies has also progressed, thanks to the excellent collaboration of sister agencies within the United Nations system. This current publication includes some of these linkages that have been recorded in recent years, in particular from 2015 to 2018, a period that experienced a strong influence of the El Niño and La Niña phenomena in addition to the long-term climate changes.
Global temperature has risen to close to 1 °C above the pre-industrial period. The time remaining to achieve commitments under the Paris agreement is quickly running out.
This report will inform the United Nations Secretary-General’s 2019 Climate Action Summit. I therefore take this opportunity to thank all the contributors – authors, National Meteorological and Hydrological Services, global climate data and analyses centres, Regional Specialized Meteorological Centres, Regional Climate Centres and the United Nations agencies that have collaborated on this authoritative publication.
2015–2018 were the four warmest years
on record as the long-term warming trend continues
Ocean heat content is at a record high and
global mean sea level continues to rise
Arctic and Antarctic sea-ice extent is
well below average
Extreme weather had an impact on lives and
sustainable development on every continent
Average global temperature reached approximately
1 °C above pre-industrial levels
We are not on track to meet climate change targets
and rein in temperature increases
Fossil CO
2 emissions have grown almost continuously for the past two centuries (Figure 4),
a trend only interrupted briefly by globally
significant economic downturns.
Emissions to date continued to grow at 1.6% in 2017 and
at a preliminary 2.0% (1.1%–3.4%) per year in
2018.
It is anticipated that a new record high of 36.9 ± 1.8 billion tons of CO
2 was reached in 2018.
Net CO
2 emissions from land use and land
cover changes were on average 5.0 ± 2.6 billion tons per year over the past decade, with highly uncertain annually resolved estimates.
Together, land-use change and fossil CO
2 emissions reached an estimated 41.5 ± 3.0 billion tons of CO
2 in 2018.
The continued high emissions have led to high levels of CO
2 accumulation in the atmosphere that amounted to 2.82 ± 0.09 ppm in 22018.3
This level of atmospheric CO
2 is the result of
the accumulation of only a part of the total CO
2emitted because about 55% of all emissions are removed by CO
2 sinks in the oceans and terrestrial vegetation.
Sinks for CO
2 are distributed across the hemispheres, on land and oceans, but CO
2 fluxes in the tropics (30°S–30°N) are close to carbon
neutral due to the CO
2 sink being largely offset
by emissions from deforestation.
Sinks for CO
2 in the southern hemisphere are dominated by the removal of CO
2 by the oceans,
while the stronger sinks in the northern hemisphere have similar contributions from both land and oceans.
OCEAN HEAT CONTENT
More than 90% of the energy trapped by GHGs goes into the oceans.
Ocean heat content is rising more.
https://reliefweb.int/sites/reliefweb.int/files/resources/1233_en.pdf