The debate that has raged in recent years about whether or not Earth is warming grew a bit more lopsided this week, with the ``official'' announcement from the climatological powers-that-be that 1998 established a new average high temperature record.
Officials with the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and the World Meteorological Organization (WMO) are in agreement that 1998 significantly exceeded the previous average worldwide temperature record, which was established in 1995 or 1997, depending on which of the organizations one believes.
And this week, scientists from the National Center for Atmospheric Research (NCAR) presented evidence suggesting that the global warming trend potentially is leading to more frequent and stronger El Nino events. Speaking at the American Meteorological Society's annual meeting in Dallas, the scientists suggest that human-produced climate changes will lead to longer, more severe droughts.
The unanimity of opinion about the new global temperature record, coupled with the strong warming trend evidenced in the past decade, has compelled a growing number of scientists to conclude that Earth is in fact in the midst of a profound warming period. But more important, a similar proportion of those same authorities also conclude that mankind is playing a role in that warming trend, although to what degree remains to be proven.
``It is really quite extraordinary,'' said NOAA Director James Baker. ``We've got a record, and it's one of the largest increases that we've ever seen in one year.'' Indeed, the average global temperature shot up a whopping 0.34 degrees Fahrenheit since 1997, making 1998 the clear leader.
Some blame has been placed on El Nino, the Pacific warm water phenomenon that wreaks havoc on global weather patterns during its periodic flare-ups. The most recent El Nino system, which late last year began to wane, was the largest yet recorded.
But scientists aren't comfortable placing all of the heat on El Nino (no pun intended). That pesky decade-long warming trend, for example, doesn't correlate well with El Nino, which only hangs around for a year or so. The 10 warmest years on record all have occurred since 1983, and seven just in the past eight years.
Also, the 1998 temperature records were measured all over the globe, something El Nino normally doesn't do. In 1998, every continent showed an appreciable increase in average temperature. In the United States, for example, temperatures were their warmest since the infamous Dust Bowl years of the 1930s.
Similarly, century-old temperature records fell across Europe (February), Russia (June), Southeast Asia (much of the year), the Middle East (summer) and India (May). Those high temperatures and an absence of rain led to severe droughts in many regions, while other regions received record rainfall totals.
Scientists at NCAR theorize that the additional heat being trapped in the atmosphere by greenhouse gases is being absorbed into the oceans, then later released in the form of El Ninos. El Nino events have occurred with greater frequency in recent years, and two of the most recent episodes broke previous temperature records. All of which is to say that rather than El Ninos having an effect on global temperatures, global temperatures are having an effect on the El Ninos.
Ocean temperatures also shattered temperature records in many regions. While El Nino was expected to raise the temperature of equatorial Pacific waters, extremely warm water temperatures also were measured in the Indian Ocean and the Atlantic Basin, including the Caribbean. Those warmer waters significantly contributed to the strength of many of the Atlantic's hurricanes in 1998, including Mitch, one of the most powerful hurricanes ever to ply the waters of the Caribbean.
Concerns over global warming prompted the controversial climate agreement in Kyoto, Japan, in December 1997, which asked that participating nations reduce emissions of carbon dioxide and other so-called ``greenhouse gases.'' That agreement did not sit well with some scientists, who argued the jury is still out on global warming. They suggested that the current warming trend could be a natural fluctuation that, relative to humanity's brief existence on the planet, is simply beyond our grasp to fully understand or appreciate. In other words, this sort of thing simply happens.
But the dramatic rise in temperatures over the past two decades, the marked elevation in greenhouse gases in the atmosphere, and the degradation of Earth's temperature control mechanisms (deforestation, for example) has forced a growing number of scientists to acknowledge that humankind is playing a role in the warming trend. ``One has to say we're seeing a combination of natural phenomena and a very strong indication of human effects here,'' said Baker. ``We're starting to get out of the range of normal climatic variability.''
Baker added that the world now has ``20 years in a row with annual global surface temperatures above the long-term average,'' suggesting that rather than some natural perturbation in temperature patterns, the world has embarked on a long-term warming trend with no end in sight.
Such a conclusion is worrisome to many scientists, who argue that warmer temperatures mean more powerful storms, heavier rains in some regions and prolonged droughts in others. Additionally, as warmer temperatures creep poleward, diseases of the equatorial regions will spread to higher latitudes.
The coming year is not expected to break 1998's temperature mark, primarily because of the waning influence of El Nino, which gradually is being supplanted by its cooling La Nina counterpart. However, 1999 is expected to continue the warming trend and to significantly exceed average temperatures.