Global Warming Controversy Vocabulary and Expressions controversy emissions non-committal projections cur

Global Warming Controversy
   The global warming controversy concerns the public debate over whether global warming is occurring, how much has occurred in modern times, what has caused it, what its effects will be, whether any action should be taken to curb it, and if so what that action should be. In the scientific literature, there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused primarily by human-induced emissions of greenhouse gases. No scientific body of national or international standing disagrees with this view, though a few organizations with members in extractive industries hold non-committal positions. Disputes over the key scientific facts of global warming are now more prevalent in the popular media than in the scientific literature, where such issues are treated as resolved, and more in the United States than globally.
   Primary issues concerning the existence and cause of climate change include the reasons for the increase seen in the instrumental temperature record, whether the warming trend exceeds normal climatic variations, and whether human activities have contributed significantly to it. Scientists have resolved many of these questions decisively in favor of the view that the current warming trend exists and is ongoing, that human activity is the primary cause, and that it is without precedent in at least 2,000 years. Additional disputes have concerned estimates of how responsive the climate system might be to any given level of greenhouse gases, projections of continued warming in response to the existing buildup of greenhouse gases plus future emissions, and what the consequences of global warming will be.
   Global warming remains an issue of widespread political debate, sometimes split along party political lines, especially in the United States. Many of the largely settled scientific issues, such as the human responsibility for global warming, remain the subject of politically or economically motivated attempts to downplay, dismiss or deny them — an ideological phenomenon categorized by academics and scientists as climate change denial.