We have a monumental task ahead

Canberra (The Conversation): Global carbon dioxide emissions from all human activities remain at record highs in 2022, and fossil fuel emissions have risen above pre-pandemic levels, according to a new analysis by an international body of scientists. The analysis, by the Global Carbon Project, calculates Earth's "carbon budget", which is how much CO2 humans have released, and how much has been removed from the atmosphere by the oceans and land ecosystems. From there, we calculate how much carbon can still be emitted into the atmosphere before Earth exceeds the crucial 1.5 degree celsius global warming threshold.

This year, the world is projected to emit 40.6 billion tonnes of CO2 from all human activities, leaving 380 billion tonnes of CO2 as the remaining carbon budget. This amount of emissions is disastrous for the climate – at current levels, there is a 50 per cent chance the planet will reach the 1.5 degree celsius global average temperature rise in just nine years. We've seen significant progress towards decarbonisation and emission reduction from some sectors and countries, particularly in renewable electricity generation.

Yet, as world leaders gather for the COP27 climate change summit in Egypt this week, the overall global effort remains vastly insufficient. Humanity must urgently cut global emissions if we are to retain any hope of averting the most catastrophic impacts of climate change. Coal and oil emissions up, gas down, deforestation slowing Based on preliminary data, we project that CO2 emissions from coal, natural gas, oil, and cement use (fossil emissions) will increase by 1 per cent in 2022 from 2021 levels, reaching 36.6 billion tonnes. This means 2022 fossil emissions will be at an all-time high, and slightly above the pre-pandemic levels of 36.3 billion tonnes in 2019.

Let's put the 2022 growth of 1 per cent (or around 300 million metric tonnes) into perspective: it's the equivalent to adding an extra 70 million US cars to the world's roads for a year it's higher than the 0.5 per cent average yearly growth of the last decade (2012-2021) but it's smaller than the 2.9 per cent average yearly growth during the 2000s (which was largely due to China's rapid economic growth) it's also smaller than the 2.1 per cent average yearly growth of the last 60 years. So, in relative terms, the global growth in fossil CO2 emissions is at least slowing down.

The growth in fossil emissions this year is largely due to higher oil and coal use – particularly oil, as the aviation industry is strongly bouncing back from the pandemic. Coal emissions have also increased this year in response to higher natural gas prices and shortages in natural gas supply. Unexpectedly, there is the possibility that coal emissions this year will be higher than the historical peak in 2014.

Another major source of global CO2 emissions is land-use change – the net balance between deforestation and reforestation. We project 3.9 billion tonnes of CO2 will be released overall this year (though we should note that data uncertainties are higher for land-use change emissions than for fossil CO2 emissions). While land-use change emissions remain high, we've seen a slight decline over the past two decades largely due to increased reforestation. Rates of deforestation worldwide, however, are still high. Together, fossil fuel and land-use change are responsible for 40.6 billion tonnes of CO2.

Nations responding to multiple turmoils The US and India are responsible for the largest increases in CO2 fossil emissions this year. US emissions are projected to increase by 1.5 per cent. While natural gas and oil emissions are higher, emissions from coal continue on a long downward trend. India's fossil CO2 emissions are projected to increase by 6per cent, largely due to an increase in coal use. Meanwhile, CO2 emissions from fossil fuel sources in China and the European Union are projected to decline this year by 0.9 per cent and 0.8 per cent, respectively. China's decline is mainly due to the nation's continuing pandemic lockdowns, which have subdued economic activity. This includes a marked slowdown in the construction sector and its associated lower cement production.

Russia's invasion of Ukraine is projected to lead to a 10 per cent decline in the European Union's CO2 emissions from natural gas in 2022, as a result of supply shortages. The gas shortage has been partially replaced with greater coal consumption, leading to an increase of 6.7 per cent in coal emissions in Europe. The rest of the world accounts for 42 per cent of global fossil CO2 emissions, and this is expected to grow by 1.7 per cent this year. Indonesia, Brazil and the Democratic Republic of the Congo contribute 58 per cent of global CO2 emissions from net land-use change. Natural carbon sinks get bigger, but feel the heat Ocean and land act as CO2 sinks. The ocean absorbs CO2 as it dissolves in seawater. On land, plants absorb CO2 and and build it into their trunks, branches, leaves and soils. This makes ocean and land sinks a crucial part of regulating the global climate. Our data shows that on average, land and ocean sinks remove about half of all CO2 emissions from human activities, acting like a 50 per cent discount on climate change. Despite this help from nature, the concentration of atmospheric CO2 continues to climb. In 2022 it'll reach a projected average of 417.2 parts per million. This is 51 per cent above pre-industrial levels and higher than any time in the past 800,000 years.

Carbon sinks are getting larger because there is more CO2 in the atmosphere for them to absorb. And yet, the impacts of climate change (such as overall warming, increased climate extremes, and changes in ocean circulation) have made land and ocean sinks, respectively, 17 per cent and 4 per cent smaller than they could have grown during 2012-2021. There's been significant progress this year in deployment of renewable energy, policy development, and commitments from governments and corporations to new, more ambitious climate mitigation targets. We must urgently reach net-zero CO2 emissions to keep global warming well below 2 degree celsius this century. But humanity's massive emissions in 2022 underscores the monumental and urgent task ahead.

(Written by Pep Canadell, CSIRO; Corinne Le Quéré, University of East Anglia; Glen Peters, Center for International Climate and Environment Research; Judith Hauck, Universität Bremen)