The concentration of carbon dioxide in the atmosphere hit 415 parts per million last week for the first time in 800 000 years. Scientists have warned that the world must keep CO2 emissions below 350 ppm to avoid dangerous levels of climate change – but emissions keep rising.
The record high was measured on May 3 at the Mauna Loa Observatory in Hawaii, part of the US National Oceanic and Atmospheric Administration (NOAA) global monitoring division.
This is the highest level recorded at this station since it began keeping records in 1959. Analysis of the ice cores in Antarctica show that over the last 800 000 years the CO2 levels in the atmosphere fluctuated between 170 ppm and 300ppm.
Climate organisations say this record high level is a strong indicator that governments must take climate change seriously and move away from fossil fuels.
Glen Tyler from the Cape Town branch of the international climate activist group 350.Org said on Tuesday that carbon emissions were now far from the "safe" target.
Far from safe
"The emissions just keep on increasing. It’s election time and our politicians need to make some tough decisions and get us out of this high carbon situation and start moving away from fossil fuels," Tyler said.
The first time carbon concentrations broke the 400ppm mark at the Mauna Loa station was on May 9, 2013, according to the NOAA. In 2015, the global concentration of CO2 went above 400ppm for the first time.
Makoma Lekalakala from the NGO Earthlife Africa said last year scientists from the Intergovernmental Panel on Climate Change had warned in the "1.5°C" report that the world had little time left – about 12 years – to make radical changes across the economy and society to cut greenhouse gas emissions.
'Governments just ignore this'
"But still we have seen temperatures rising. It doesn’t seem like an issue, or to be taken seriously. Governments just ignore this," Lekalakala said.
"For example, the South African government is committed on paper to reducing emissions, but the addiction to coal in South Africa, like China, is not lessening. Scientists warned last year that we have very little time left, because temperatures are rising. We need a rapid transition to a low carbon economy."
Earlier this year Pieter Tans, a senior scientist with NOAA’s global monitoring division, said three of the four highest annual increases in carbon had occurred in the past four years.
"At a time when there’s all this talk about how we should be decreasing CO2 emissions, the amount of CO2 we’re putting into the atmosphere is clearly accelerating," Tans said.
Carbon emissions are driven mainly by burning fossil fuels.
Tans said then that it was no co-incidence that CO2 emissions had grown at record rates, because consumption of coal, oil and natural gas were also at historically high levels. NOAA tracks five main greenhouse gases that warm the planet by trapping heat from the Earth’s surface that would otherwise escape into space.
The organisation said these five gases accounted for about 96% of the atmosphere’s increased heat-trapping capacity since 1750, the pre-industrial era.
Suzanne Carter, programme manager for SouthSouthNorth, an NGO that supports responses to climate change through collaboration, said the Mauna Loa station had the longest recorded direct measurements of CO2. The fact that the high CO2 concentration recorded there last week had never been recorded before, showed that levels were continuing to rise "despite our best efforts to curb emissions".
"A lot more needs to be done to increase our green energy sources and reduce emissions. We need to get serious about meeting the Paris Agreement commitments. If not, we risk accelerating negative climate impacts, which as we know are greater in already vulnerable regions, like Africa," Carter said.
NOAA captures and analyses air samples from a network of observatories and collecting stations around the world.
Prehistoric levels of carbon in the atmosphere are obtained from drilling ice-cores in Antarctica. This multi-national programme is run by the European Project for Ice Coring in Antarctica (EPICA).
Ice cores are drilled up to a depth of about 3.2km, which contain ice of up to 800 000 years old. The ice contains bubbles that have trapped the gas concentrations of the earth’s atmosphere over time, so prehistoric CO2 levels can be measured.
Analysis of the ice cores show that over the last 800 000 years the CO2 levels in the atmosphere fluctuated between 170 ppm and 300ppm.
The highest level recorded in the ice cores during this time – excluding the time since industrialisation – was 298 ppm. This was recorded about 330 000 years ago.
EPICA records that CO2 levels in the ice core samples have increased markedly in industrial times. Measurements at the south pole in 2010 showed 386 ppm.