Is global warming due to human actions? Can the human race take action to stop global warming?

Is global warming due to human actions? Can the human race take action to stop global warming?

Introduction

The phrase global warming refers to a phenomenon in which the Earth's surface temperature increases from its long-term averages generally because of an atmospheric blanket of greenhouse gases (GHGs; primarily carbon dioxide, methane, and chlorofluorocarbons) that serve to trap reradiated solar energy from escaping into space. This blanket of greenhouse gases is responsible for providing Earth a generally temperate, stable, and life-sustaining climate. In common parlance, global warming is often used interchangeably with climate change. In the present context, though, it is used in a more limited sense as a driver of global climate change.

Since the onset of the industrial revolution (c.1750), human activities have altered the atmospheric composition of the Earth, significantly impacting the terrestrial energy balance. The burning of fossil fuels has substantially increased the amount of particulate matter and concentration of greenhouse gases (GHGs), most notably carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), into the atmosphere. The overall impact of human industrial activities on global climate has been a pronounced warming effect, as GHG increases have enhanced the atmospheric greenhouse effect and reduced the amount of outgoing radiation from the Earth. Although global climate change occurs with natural process (e.g., volcanic eruptions, insolation variability), the rate of change is much slower, occurring over millennia rather than the rapid anthropogenic induced climate changes observed over the past century with the modern industrial era. Global climate change impact scenarios have sparked an international debate on policy initiatives for balancing global climate change reduction measures with continued industrial development.

Background

“Climate change” is closely related to “global warming” but can be thought of as a more complex set of phenomena, many of which are directly dependent on global warming. Discussed elsewhere in this volume, global warming is a phenomenon that results from radiative forcing as a result of various gaseous and particulate substances in Earth's atmosphere. The increase in Earth's mean surface temperature is caused by warming of land, ocean, and/or atmosphere as a result of the amount of the sun's radiant energy that is not reradiated into space but absorbed by the Earth and it components.

Discussion

Sources of this global warming are natural or anthropogenic. Absent human influence, naturally occurring GHGs (including carbon dioxide) and water vapor (in the form of clouds) provide a relatively stable radiative forcing that maintains the global mean surface temperature at a level conducive to human and other biological life. Abrupt warming may result from variations in solar radiation patterns. Abrupt cooling may result from the reflection back into space of greater amounts of solar radiation by dust resulting from volcanic activity.

A change in global mean surface temperature from global warming results in a variety of physical and chemical changes to Earth systems that often manifest themselves in weather events (such as hurricanes or thunderstorms). The long-term (regional) “average” of these weather events determines ...