Global warming has raised global temperature by an average of 1.1° C. Climatic patterns like El Nino and La Nina impact weather. With temperatures already at least 1° C above pre-industrial levels, the impact of these climatic patterns is magnified. The high levels of atmospheric GHGs also affect weather systems, which, in turn, aggravate the impacts of unchecked global warming.
The jet stream – giant airstreams – circles Earth‘s northern hemisphere in huge turns, waving up and down between the Arctic and the Equator. These planetary waves transport heat and moisture, thereby influencing the weather. Studies show that increased global warming leads to conditions that stall the movement of these waves, resulting in extended extreme heat events in parts of the northern hemisphere. The warming of the Arctic has meant weather systems that carried cold air from the north to south no longer doing so. There should be no doubt of the urgent need to reduce GHG emissions. Some changes are unlikely to be reversed, especially in the short term. But what can be avoided is further deterioration.