2013 climate year in review

The end of the year is usually the time to evaluate the year. In 2013 the concentration of climate-warming carbon dioxide in the atmosphere passed the milestone level of 400 parts per million for the first time in human history. How much more dioxide emissions people can release in the atmosphere without speeding up dangerous climate change? Scientists have concluded that more than half of the "carbon budget" has already been spent. There are no doubts now that the observed global warming is man’s handiwork, and there is no time left to think, whether to act.

Damian Carrington, the article author, gave it the title "The heat is on. Now we must act." He considers May 10, 2013 - the date when the concentration of climate-warming carbon dioxide in the atmosphere passed the milestone level of 400 parts per million for the first time in human history - one of the most important milestones in the past year. The last time so much greenhouse gas in the air was several million years ago, when the Arctic was ice-free, savannah spread across the Sahara desert and sea level was up to 40 metres higher than today.

The release of the next report of the Intergovernmental Panel on Climate Change (IPCC) became another significant event of the year. The report has a distinctive feature: scientists unanimously recognized that there is no doubt that the global warming is a result of human activity. The authors pointed out that, without "substantial and long-term" emission reduction, the 2-degree warming limit established by governments will be violated, and it will lead to strong heat, drought and more extreme weather conditions. The IPCC report also notes that the sea level could rise by 26-82 cm by 2100, and some scientists believe that these figures are underestimated.

The most questionable moment in the IPCC report, according to Guardian, was a statement about how much more dioxide emissions people can release in the atmosphere without causing dangerous climate change. Scientists have concluded that more than half of the "carbon budget" has already been spent.

The consensus of climate scientists on the cause of global warming had been emphasised in May, when a study of thousands of research papers published between 1991 and 2011 showed 97 % endorsed human-caused global warming.

However, the scientific consensus was not matched by consensus on a political deal. The annual meeting of the UN's climate body, the UNFCCC, took place in November in coal-friendly Poland, and concluded by sending nations away to "do their homework." The answer to the question, which nations should cut their emissions and by how much, is still to be found.

Notably, the new Australian government led by Tony Abbott – who has called climate change "crap" – failed to send a minister to the UN climate talks but set about dumping the country's nascent carbon tax. Meanwhile, Australia's spring was the warmest on record, reports Guardian.

Meanwhile, the big two global emitters – China and the US together cause 40% of emissions – agreed in July to expand their joint efforts against climate change. According to analysts, this move raises the prospects for an eventual global climate deal. The agreement covered cleaner vehicles, carbon capture technologies, energy efficiency and smart grids.

In addition, 2013 also saw China establish carbon trading schemes in Beijing, Shanghai and Shenzhen, which may help address appalling air pollution problems. Such schemes, where permits to pollute are traded are seen by many as the cheapest way of cutting emissions. However, the world's biggest scheme – the EU's – saw only modest progress in addressing the glut of permits that is holding the carbon price at rock-bottom levels.

In his assessment of the climate outcomes in 2013, the Guardian analyst comes to conclusions similar to the position of public environmental organizations: what is happening serves as "a sobering reminder that greenhouse gas emission is continuing unabated, despite ever more certainty that the burning of fossil fuels and deforestation is on track to end the millennia of relatively stable climate during which human civilisation has flourished." There is no time to discuss, whether climate change is real. It is time to act!