A team of international researchers says that climate change made recent flooding in southern Brazil twice as likely to happen.一组国际研究人员表示，气候变化使巴西南部最近发生洪水的可能性增加了两倍。
It also said that the El Nino Pacific Ocean current made the rains in Brazil more severe.报告还表示，厄尔尼诺太平洋洋流使巴西的降雨更加严重。
Last month, flooding killed more than 170 people and displaced nearly 580,000 in Brazil's southern state of Rio Grande do Sul.上个月，巴西南部南里奥格兰德州洪水造成170多人死亡，近58万人流离失所。
Local officials said it was the worst disaster in the area's history.当地官员表示，这是该地区历史上最严重的灾难。
A network of experts called World Weather Attribution said that the heavy rainfall in Rio Grande do Sul was an "extremely rare" event.一个名为“世界天气归因”的专家网络表示，南里奥格兰德州的强降雨是“极其罕见”的事件。
The group said it expects such an event to happen only once every 100 to 250 years.该组织表示，预计此类事件每100至250年才会发生一次。
However, the group added, it would have been even rarer without the effects of burning fossil fuel.然而，该组织补充说，如果没有燃烧化石燃料的影响，这种情况会更加罕见。
The experts at World Weather Attribution also said the flooding was six to nine percent more severe than it would have been without climate change.世界天气归因组织的专家还表示，洪水的严重程度比没有气候变化的情况下高出6%至9%。
The experts combined weather observations with results from climate models to make their estimates.专家们将天气观测与气候模型的结果结合起来做出估计。
Lincoln Alves is with Brazil's space research center INPE.林肯·阿尔维斯就职于巴西太空研究中心INPE。
Alves said, "The climate in Brazil has already changed."阿尔维斯说：“巴西的气候已经发生了变化。”
He said that the study "confirms that human activities have contributed to more intense and frequent extreme events…"他说，这项研究“证实了人类活动导致了更激烈、更频繁的极端事件……”
He added that the flooding showed Brazil's vulnerability to climate change.他补充说，洪水表明巴西易受气候变化的影响。
The researchers said that the El Nino Pacific Ocean current also played a part in the flooding in Brazil.研究人员表示，厄尔尼诺太平洋洋流也对巴西的洪水产生了一定的影响。
Experts say the El Nino phenomenon contributes to higher temperatures in many parts of the world.专家表示，厄尔尼诺现象导致世界许多地区气温升高。
It also brings increased rainfall and flood risk to parts of the Americas.它还增加了美洲部分地区的降雨量和洪水风险。
The scientists added that failure of important infrastructure, deforestation, and the fast growth of cities helped to increase the effects of the disaster.科学家们补充说，重要基础设施的故障、森林砍伐和城市的快速发展加剧了灾难的影响。
The flooding affected Porto Alegre, the capital of Rio Grande do Sul.洪水影响了南里奥格兰德州首府阿雷格里港。
The city is home to 1.3 million people.这座城市拥有130万人口。
Regina Rodrigues is a researcher at the Federal University of Santa Catarina.雷吉娜·罗德里格斯是圣卡塔琳娜联邦大学的研究员。
She said that good flood protection infrastructure and the right urban planning are needed to reduce the effect of "such extreme events."她说，需要良好的防洪基础设施和正确的城市规划来减少“此类极端事件”的影响。
