Climate Change

Introduction

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 (Zedillo, 78).

Global climate change impact scenarios have sparked an international debate on policy initiatives for balancing global climate change reduction measures with continued industrial development.

Even if human ingenuity and/or behavior resulted in the total cessation of anthropogenic GHG emissions tomorrow, the persistence of these gases in the atmosphere and the inertia of the geophysical, oceanic, and atmospheric processes that feed off global warming will result in a global mean surface temperature rise approaching at least 2 degrees C over the next century. Given the current rate of GHG emissions growth, in spite of any individual and collective reduction efforts, we are almost certain to cause much more warming still.

Thesis Statement

“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”.

Discussion and Analysis

“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.

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 what we term our climate and defines the weather we expect at any particular time of year at any place on the globe. The change in well-established climate patterns is recognized as climate change.

Although isolated weather incidents ...