To understand global warming and cooling, we understand the difference between climate and weather. Much of the argument for or against global warming and cooling is laden with confusion between climate and weather. How can we have global warming when there are places that are encountering record cold temperatures?
Weather concerns the specific events that are going on in specific places at a specific time, and does not concern the entirety of the world’s climate. A record snow storm in London may be occurring at the same time as record breaking heatwave in Botswana.
Climate is the average of these events that are recorded over time, at least in decades with modern technology, but in many cases, over a hundred years or more.
Climate is what is forecasted using the best means available, while weather is what actually happens.
The studies of both weather and climate are done on a variety of specific activities, scales and measurements of natural and atmospheric phenomena. Depending on what component or area it is that a meteorologist is interested in, attempts are made to define what is “normal” and what is a “variation from normal”. These studies are aggregated to a global level in order to understand “normal” and “variation from normal” on a planetary scale.
As a result, global aggregations of such measurements as the global atmospheric levels of carbon dioxide and pollutants; the average temperature of the atmosphere; the melting and freezing of the polar ice caps, and the conditions of the oceans which contribute the most oxygen/carbon dioxide processing to our atmosphere are all important.
“Greenhouse gases”, or Carbon Dioxide (CO2), are believed to contribute to increases in the average temperature of the entire Earth’s atmosphere. As a result, when the global average atmosphere temperature increases at the same time that measurements of certain “greenhouse gases” show increases, it is hypothesized that there is a direct relationship between the two, where an increase in the causative variable: the greenhouse gases, causes an increase in the dependent variable: the atmosphere.
Whether the increase in CO2 is caused by man or whether it is a normal consequence of nature, there is a connection between higher CO2 and overall average rises in the Earth’s atmosphere. Economic conditions, for example, can affect human activity to increase or decrease human CO2 production, as economic conditions rise and fall.
Global warming and cooling, therefore, involve the entire atmosphere of the entire planet based on data that is collected over long periods of time. This is why the exact opposite of the overall warming or cooling will be going on at one specific place or another at any given time, giving the mistaken impression that global warming or cooling is disproved or proven depending on where we are and what day it is!
There are actually no ways to accurately measure the entire atmospheric temperature of the Earth. There are regions where the data is sparse or difficult to obtain on a consistent basis. As a result, there are many different ways of calculating the average temperature of the entire atmosphere.
Since there are many different measures of global warming that do not agree with each other, global warming is actually best identified as anomolies that vary from average baselines that are established over the years.
Is there global warming? The average temperature of the Earth’s atmosphere during the 20th century was the highest, in 1998. For the past decade, the average temperature has remained flat, with 2008 as the coolest average temperature of the decade.
The general expectation is that the average warming will increase over the next decades, with breaks in the warming trend that are based on volcanic activity, El Nino events, and the solar cycle.