Global carbon dioxide emissions increased by 45 percent between 1990 and 2010, reaching a record high 33 billion tons last year, according to a report by the European Commission’s Joint Research Center. The report said that increased energy efficiency, renewable energy, and nuclear power are not compensating for a surge in emissions from developing countries, most notably China — with a 257 percent increase in CO2 emissions from 1990 to 210 — and India, whose emissions increased by 180 percent. By contrast, the European Union’s emissions declined by 7 percent from 1990 to 2010, and Russia’s dropped 27 percent. U.S. emissions increased by 5 percent from 1990 to 2010. After a slowdown in CO2 emissions at the height of the recession in 2008 and 2009, global emissions saw a record-breaking increase of 5.8 percent from 2009 to 2010, the report said. Meanwhile, a study in the journal Climate Change Letters said that even if average global temperature increases can be held to 2 degrees C (3.5 F) this century — an increasingly unlikely prospect — 70 to 80 percent of the globe’s land surface will experience summertime temperatures that exceed observed historical extremes in at least half of all years.