Your weather when it really mattersTM


Please choose your default site


Asia - Pacific


Greenhouse gases hit record high with 'no sign of slowdown', UN report

Tuesday, November 26th 2019, 2:20 pm - Carbon emissions are increasing at an alarming rate, according to the report.

The concentration of greenhouse gases in the atmosphere hit a record high that Earth has not experienced for 3 to 5 million years, according to a new report from the UN’s World Meteorological Organization (WMO).

The globally averaged concentrations of carbon dioxide (CO2) reached 407.8 parts per million in 2018, up from 405.5 parts per million (ppm) in 2017. Climate scientists have considered 400 ppm as a symbolic threshold that should have never been crossed and many consider 350 ppm to be a safe level.

The concentration of carbon dioxide has fluctuated throughout Earth's history. During ice ages, CO2 levels were around 200 ppm and rose to 280 ppm during warmer interglacial periods. Human activity, such as burning fossil fuels, has sent CO2 levels soaring over the past few decades and for the first time in recorded history CO2 levels surpassed 400 ppm in 2013.

Scientists are able to determine which greenhouse gases were released by humans and which are released by natural processes. The fossil fuels that we burn for energy were formed by decomposing plant material millions of years ago and do not contain radiocarbon, which is an isotope of carbon. The radiocarbon-free CO2 has been recorded over time and correlated to the rising temperatures since widespread fossil fuel use began in the early 1900s.

The report states that the significance of this record high is that carbon emissions are increasing at an alarming and says that “future generations will be confronted with increasingly severe impacts of climate change, including rising temperatures, more extreme weather, water stress, sea level rise and disruption to marine and land ecosystems.”

The relationship between carbon dioxide emissions and rising temperatures is the most commonly cited indication that the changes in the climate are caused by humans. The last time that Earth experienced CO2 levels over 400 ppm was when temperatures were 2 to 3C warmer and sea levels were 10 to 20 metres higher than present-day, states WMO Secretary-General Petteri Taalas in the report.

If greenhouse gas emissions continue on a business-as-usual trajectory, the concentration of CO2 could exceed 1000 ppm after the year 2100. Climate scientists say that the 350 ppm of CO2 is the safe level because exceeding this threshold would cause global temperatures to warm to levels that could endanger global food supplies, contribute to increased frequency and severity of extreme weather, and accelerate sea level rise.

Methane and nitrous oxide are other greenhouse gases that have been rapidly rising over the past century. Atmospheric methane reached a new high of 1869 parts per billion (ppb) in 2018 and approximately 60 per cent of this greenhouse gas comes from cattle breeding, rice agriculture, fossil fuels, landfills and biomass burning. Nitrous oxide emissions in 2018 were 331.1 ppb, which is 123 per cent of pre-industrial levels, and approximately 40 per cent of this greenhouse gas came from oceans, biomass, soil and fertilizer.

So what can we do? The records that were recently broken are concerning, but knowing the cause of the problem means that we understand how to create solutions. The report states that commitments made in the 2015 Paris Agreement by parties and signatories must be put into action and level of ambition should be raised.

The Science Advisory Group to UN Climate Action Summit 2019 states that decarbonizing the energy supply is essential for reducing greenhouse gas emissions in the transportation sector, phasing out coal, and investing in resource that capture carbon, such as forests and other terrestrial ecosystems, are realistic changes that the world can make to prevent catastrophic effects from climate change.


Thumbnail image courtesy: Getty

Default saved

Search Location


Sign In

Please sign in to use this feature.