Concentrations of carbon dioxide (CO2) in the atmosphere last year were the highest in 800,000 years, according to the World Meteorological Organisation.
A report in its Greenhouse Gas Bulletin highlighted that the levels of CO2 surged due to a combination of human activities and a strong El Niño weather event. Concentrations of CO2 are now 145 per cent of pre-industrial (before 1750) levels, it stated.
Rapidly increasing levels of CO2 and other greenhouse gases in the atmosphere could cause unprecedented changes in climate systems, for example a more extreme climate, the report revealed.
The annual bulletin is based on observations from the WMO Global Atmosphere Watch Programme.
Population growth, agricultural practices, increases in land use and deforestation, industrialisation and associated energy use from fossil fuel sources have all contributed to increased concentrations of greenhouse gases.
WMO Secretary-General, Petteri Taalas,said: “Without rapid cuts in CO2 and other greenhouse gas emissions, we will be heading for dangerous temperature increases by the end of this century, well above the target set by the Paris climate change agreement.
“Future generations will inherit a much more inhospitable planet.
“CO2 remains in the atmosphere for hundreds of years and in the oceans for even longer. The laws of physics mean that we face a much hotter, more extreme climate in the future. There is currently no magic wand to remove this CO2 from the atmosphere.’
The last time the Earth experienced a comparable concentration of CO2 was 3-5 million years ago, the temperature was 2-3°C warmer and sea level was 10-20 metres higher than now.
A separate Emissions Gap Report by UN Environment, due to be released today (31 October), tracks the policy commitments made by countries to lower greenhouse gas emissions and looks at how the policies will translate into emissions reductions through 2030.
Erik Solheim, head of UN Environment, said: “The numbers don’t lie. We are still emitting far too much and this needs to be reversed. The last few years have seen enormous uptake of renewable energy, but we must now redouble our efforts to ensure these new low-carbon technologies are able to thrive.
“We have many of the solutions already to address this challenge. What we need now is global political will and a new sense of urgency.”
The Greenhouse Gas Bulletin and Emissions Gap Report provide a combined scientific base for decision-making at the UN climate change negotiations, to be held from 7-17 November in Bonn, Germany.
WMO, UN Environment and other partners are working towards an Integrated Global Greenhouse Gas Information System, which will help nations track the progress toward implementation of their national emission pledges and improve national emission reporting.
The system builds on the long-term experience of WMO in greenhouse gas instrumental measurements and atmospheric modelling.
WMO is also working towards improving weather and climate services for the renewable energy sector and to support the Green Economy and sustainable development.