Will 2010 Be The Warmest Year Ever Recorded?
 Measured world wide, it could happen that 2010 may become the warmest year ever recorded. If not, it is certainly going to be either one of the warmest years ever recorded in the climatic history of the globe according to a recently released report of the National Climatic Data Centre(NCDC) of the National Oceanic and Atmospheric Administration (NOAA) of the Department of Commerce of the United States of America.
There is now a great deal of scientific evidence that the Earth’s climate is changing according to this authorative report, to which 300 scientists from research groupings in 48 countries contributed. The report confirms conclusively that the past decade was the warmest ever recorded and the earth has become progressively warmer during the past 50 years. While for many the 1 degree Fahrenheit increase in temperature during the last 50 years may appear small, it nonetheless has already brought about major changes.
The USA`s NASA has measured the surface temperature of the earth during the first six months of 2010 as the highest in 131 years. According to the NCDC eight countries in Asia, Africa and parts of the former Soviet Union, earlier this year, recorded the highest temperatures ever measured in those countries. Elsa de Jager of the South African Weather Service(SAWS) was more guarded in making any predictions but confirmed that South Africa, like other regions, was also experiencing increasing global temperature but this did not mean that this year will be warmer than 2009.
How Do We Know The Earth’s Climate Is Warming?
Thousands of land and ocean temperatures are recorded each day around the globe by weather stations, ships, aircraft and buoys in the oceans. A warming trend is apparent and is confirmed by many independent agencies around the world. In addition, there is a mass of evidence of reduction of snow cover, earlier blooming of plants in spring, a shorter ice season on lakes and rivers, reduced arctic ice and rising sea levels.
The Global Surface Temperature Is Rising
Global average temperature is one of the most referenced indicators of global change and shows an increase of approximately 1.4 F since the commencement of the 20th Century. The 20 warmest years all occurred since 1981 and the 10 warmest have all occurred in the past 12 years.
The USA Surface Temperature Is Also Rising
Surface temperatures averaged across the USA have and are still rising despite the surface of the USA being a fraction of the world’s surface. This is subject to more year-on-year variations than the planet as a whole.
The Sea Level Is Rising
Global mean sea level has been rising at an average rate of approximately 1.7 mm /year over the past 100 years (measured from tide gauge observations). Since 1993, the global sea level has risen at an accelerated rate of around 3.5 mm/year.
Global Upper Ocean Heat Content Is Rising
Despite ocean heat content varying from place to place and from year-to-year, there is a strong trend of increasing expansion of the upper ocean as the water temperature increases.
Northern Hemisphere Snow Cover Is Retreating
Northern Hemisphere average snow cover has declined in recent decades. Some of the largest declines have been recorded in the spring and summer months.
Glacier Volume Is Shrinking
Warmer temperatures lead to the melting of glaciers and ice sheets. The total volume of glaciers on earth is declining alarmingly. The progressive disappearance of glaciers has implications for a rising global sea level, but also for water supplies in certain regions of Asia and South America.
The USA Climate Extremes Are Increasing
" Extreme" climate events (meaning the most rare temperature, precipitation and storm intensity ) is now measured in the USA by means of the Climate Extremes Index (CEI) . The number of extreme climate events in the USA has been rising over the last four decades.
How Do We Know Humans Are The Primary Cause Of The Warming?
There is a considerable body of evidence supports the conclusion that human activity is the primary driver of global warming. The first line of evidence is our better understanding of how greenhouse gases trap heat and how the climate responds to increases in green house gases. Another line of evidence is from indirect estimates of climate changes over the last 1 000 or 2 000 years such as tree rings and corals.
Climate Model Indications and the Observed Climate
Global climate models clearly show the effects of human-induced changes on global temperatures compared with natural changes.
800 000 Year Record of Carbon Dioxide Concentrations
The concentration of carbon dioxide has increased by approximately by 35 percent since the advent of the industrial revolution. Globally, over the past several decades, about 80 percent of human- induced carbon dioxide came from the burning of fossil fuels, while about 20 percent resulted from deforestation and associated agricultural practices.
Energy from the Sun Has Not Increased
The amount of solar energy follows a natural 11-year cycle of small variations but with no net increase, yet over the same period global temperature has risen markedly. This indicates that it is unlikely that solar influence has been a driver of global temperature change over several decades.
Pieter Rautenbach
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