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 can or 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 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, and some have tried to persuade the public that climate change is not happening, or if the climate is changing it is not because of human influence, attempting to sow doubt in the scientific consensus.

As of 2022 the U.S. National Oceanographic and Atmospheric Administration says the global yearly average temperature has been warming at rate of 0.18 °C (0.32 °F) per decade since 1981.

The controversy is, by now, political rather than scientific: there is a scientific consensus that global warming is happening and is caused by human activity. Disputes over the key scientific facts of global warming are more prevalent in the media than in the scientific literature, where such issues are treated as resolved, and such disputes are more prevalent in the United States and Australia than globally.

Political and popular debate concerning the existence and cause of global warming includes 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 answered these questions decisively in favor of the view that the current warming trend exists and is ongoing, that human activity is the cause, and that it is without precedent in at least 2000 years. Public disputes that also reflect scientific debate include estimates of how responsive the climate system might be to any given level of greenhouse gases (climate sensitivity), how the climate will change at local and regional scales, and what the consequences of global warming will be.

Global warming remains an issue of widespread political debate, often split along party political lines, especially in the United States. Many of the issues that are settled within the scientific community, such as 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. The sources of funding for those involved with climate science opposing mainstream scientific positions have been questioned. There are debates about the best policy responses to the science, their cost-effectiveness and their urgency. Climate scientists, especially in the United States, have reported government and oil-industry pressure to censor or suppress their work and hide scientific data, with directives not to discuss the subject in public communications. Legal cases regarding global warming, its effects, and measures to reduce it have reached American courts. The fossil fuels lobby has been identified as overtly or covertly supporting efforts to undermine or discredit the scientific consensus on global warming.