Task 221. In the twentieth century, soot22. If snow and ice covered areas begin melting, 23. A soot forcing is unusually effective, which24. Hansen cautioned that greenhouse gases25. Warming in the Northern Hemisphere was large in at middle and high latitudes. A. produces much more global warming than a carbon-dioxide forcingof the same magnitudeB. contributed to 25 percent of observed global warmingC. winter and springD. the warming effects increaseE. still surpass soot in warming the world's climate during thelast centuryF. can be seen mostly in the Northern Hemisphere
As discovered by expedition scientists, Antarctica has not always been so cold as it is today, so hasthe Arctic.