Differences between 'Climate Change' and 'Global Warming'

N Munal Meitei *

De-forestation in Manipur

Many people even in the media and elsewhere use the terms "Climate change" and "Global warming" interchangeably, as if they are the same thing. But there are differences between the meanings of the two terms. Getting a better handle on the definitions of and differences between the two will help us to understand why the threat caused by the continued warming of the planet is so serious.

Planet Earth's current warming trend is based largely on natural warming and cooling cycles that have been happening for eons; as well as human-caused additions to greenhouse gases, which are boosting the atmosphere's ability to trap the solar heat in the biosphere. Minor factors like an overall increase in the Sun's solar intensity play a smaller role. The climate at most locations is not steady or regular.

The meaning of 'climate change' is fairly straightforward - a clear, sustained change in the components of climate, such as temperature, precipitation, atmospheric pressure, winds and ocean current that often differ from the mean state i.e. the long term or from the annual cycle. These variations occur on a variety of time scales, from year-to-year, e.g. El Niño and La Niña, decade-to-decade, e.g., Hydrologic and fisheries cycles, to centuries e.g., Ice ages etc.

Such changes must constitute a clear trend, and be clearly distinguished from the small random variation in these parameters that takes place all the time. That is why climate change can only be determined after careful analysis of several decades of observations. In this context, it is important to understand clearly the difference between climate and weather.

Climate may change in a single region or across the whole planet. Throughout earth's history, climates have changed. The causes are various. Change can be brought about by a variety of factors which include natural external factors, such as changes in solar emission or slow changes in the earth's orbit; or natural internal processes of the climate or earth system such as volcanic activity; or, as having these days, the humaninduced anthropogenic factors.

A similar trend that is widespread over of much of the earth may be a sign of 'Global Climate Change'. Global climate change is often commonly referred to as Global Warming, because of the apparent steady increase in global temperature over the past century. Global warming which is not considered a technical term refers to an increase in the average temperature at the surface of the earth, or the lower part of the atmosphere. Most climatologists consider that the global warming that we are now experiencing is mainly the result of human actions changing the composition of the atmosphere. However, global warming and cooling have occurred naturally throughout the history of the earth, as a result of natural climate variability.

Such changes in the past were usually much slower than the rate of warming that has occurred in the last few decades. This is a consequence of growing levels of greenhouse gases, most notably carbon dioxide (CO2). These gases trap the infrared radiation from the earth and redirect it back to the earth's surface. Water vapor is by far the most important greenhouse gas, accounting for about 90% of the natural greenhouse effect. However only small increases in the other greenhouse gases, such has occurred over the past century, can warm global temperature via the amount of heat trapped in the atmosphere. While CO2 concentrations in the atmosphere have varied naturally over geological time scales, the burning of fossil fuels by humans is the overwhelming source of increased atmospheric CO2 in recent times.

Methane, produced by increased rice cultivation and livestock production, is another greenhouse gas. Others include chlorofluorocarbons (CFCs), which are artificial compounds associated with refrigeration and soil fumigants, and nitrous oxide - for example smog - from internal combustion engines. Recent studies indicate that these non-CO2 greenhouse gases have contributed significantly to Global warming in recent decades.

Long-term variations in other factors – solar energy emission, volcanic gas and dust levels, and the storage and redistribution of heat in the deep ocean – impact the Earth's climate and may produce a Global Warming trend. Separating the role and degree of human impacts from natural variation in climate remains a complex and challenging scientific question. A critical question is whether human activity is altering the climate more rapidly than ecosystems and society can adapt. A second question is to what degree that civilization is willing – and able– to adapt to the combined effect of natural and anthropogenic climate change.

The increase in global temperatures has the potential to seriously disrupt many of the environmental, economic and political structures upon which human society depends. The various components of the climate and earth system are inextricably linked through complex feedback mechanisms, and a change in one component such as temperature will induce changes and adjustments in other components.

Other changes that have either already been observed or are projected to occur as a result of human activity include sea level rise; changes in rainfall patterns; increases in extreme weather events; decreases in ice mass of glaciers, ice sheets and sea ice; ocean warming and acidification; changes in ocean circulation; and drying of the land.

Need to understand both Climate Change and Global Warming While greenhouse gases are an essential component of a livable planet – they're what keep Earth from being a lifeless ball of ice at around minus15°C – humans are causing greenhouse gas levels to increase so quickly that it's causing the average global temperature to rise much faster and giving the extreme weather as it would be than it would naturally. This warming is predicted to lead to a variety of negative effects, including:

1) Melting and possible disappearance of glaciers and mountain snow caps that feed the world's rivers and supply a large portion of the fresh water used for drinking and irrigation.

2) A rise in sea levels due to the melting of the land-based ice sheets in Greenland and Antarctica, with many islands and coastal areas ending up more exposed to storm damage or even underwater.

3) Increasingly costly "bad weather" events such as heat waves, droughts, floods, and severe storms. 4) Lowered agricultural productivity due to less favorable weather conditions, less available irrigation water, increased heat stress to plants, and an increase in pest activity due to warmer temperatures.

5) Increases in vector-borne infectious diseases like malaria and Lyme disease.

6) Large numbers of extinctions of higher-level species due to their inability to adapt to the rapidly changing climate and habitat conditions. Climate change is about much more than how warm or cool our temperatures are. Whereas global warming refers to increasing global temperatures, 'climate change' refers to regional conditions.

It's tempting to think that all of these changes to the world's climate regions will average out over time and geography and things will be fine. In fact, colder climates like Greenland including Canada may even see improved agricultural yields as their seasonal temperatures rise. But overall, humanity has to make a huge investment in "things as they are now, where they are now." Gone are the days of millennia ago when an unfavorable change in climate might cause a village to pack up their relatively few belongings and move to a better place.

We have massive societal and industrial infrastructures in place and it cannot be easily moved. Therefore for the present climate-change and global warming, it would not be a geographically escapable in the timeframe over which they happen, for whole living beings on the earth. One of the most devastating effects of global warming is an impact on tropical storms. Hurricanes have been energized when they picked up warmer than normal ocean water.

There has been a significant increase in these higher intensity storms over the last 35 years and it has reached from category 3 to 4 and now to category 5 such as Hurricane Katrina which is the costliest hurricane in American history. Earth's ice is crucial in order to maintain the delicate balance in the environment. As global warming causes temperatures to rise in the oceans, glaciers and icecaps are melting more rapidly.

The polar ice cap is dissolving at an astonishing rate as well–9% per decade. This recent phenomenon is a definite cause for alarm. In the last half century, the thickness of ice in the Arctic has decreased by 40%. Global warming has the potential to make the earth a very inhospitable place to live. It is expected a rise of about 6°C by 2100. Rising temperatures in ocean waters are a clear indication that the process has begun. It is up to the people of the world to do what they can to stop or slow this alarming environmental problem.

Now the real question is whatever the meaning of the two it may be; our concern is its impact to our future. It is no longer easy to deny that the climate is changing and the Planet is warming. The risk is that it may change quicker than we can fully understand and accept to adapt it. We could easily be caught unprepared for this. Therefore, think of a way to save our environment initiating from your nearest surrounding right now because tomorrow will be too late. Let us plant more trees and save our environment and ultimately the Planet.