Global Warming Since 1998
Duke University
by Dr. Bill Chameides - Duke University Professor, Dean of Duke University Nicholas School of the Environment, Member of the National Academy of Sciences, Fellow of the American Geophysical Union .
October 28th, 2008
(excerpts)
You don’t have to search too hard to find a skeptic’s blog proclaiming that global warming “stopped” in 1998. Oh happy day if it were true, but sadly it is not. Why do I say this? I’ve looked at the data. Take a look at the graphic below, which shows the average global temperatures from 1990 to the present. The green diamonds show the 5-year averages for the periods from 1988–1992, 1993–1997, 1998–2002, and 2003–2007. Each successive diamond appears at a higher temperature than the one before. In other words, global temperatures have been increasing over the past 15+ years — global warming has not stopped.
Global temperature trends since 1990. Solid line with small dots indicate the annual averages. The green diamonds indicate the 5-year averages. Data taken from the Carbon Dioxide Information Analysis Center at the Oak Ridge National Laboratory: CDIAC Temperature Data Sets
If you look at the temperatures in the graphic year by year, it’s easy to see why someone might think that the warming has stopped. After all, there was a huge temperature maximum in 1998. Since then, only 2005 [and now 2010] had average temperatures equal to or perhaps slightly greater than those in 1998. Eyeballing temperatures from 1998 onward might lead to the inference that temperatures have not increased at all -– that global warming has stopped. But wait. If you do the same eyeballing exercise starting in 1999 or 1996 you would conclude that there has been a rapid increase in temperatures. Moreover, if you were back in 1992 or 1993 and had done the same eyeballing exercise back to 1990, you would have concluded that global warming had stopped; and you would have been wrong. So what’s the problem? It comes from a confusion between inter-annual and short-term temperature changes and the longer-term changes in temperatures that are relevant to the issue of climate change on decadal time scales.
There are any number of factors that cause global temperatures to rise and fall. Solar activity is one –- as the sun goes through its 11-year sunspot cycle, solar radiation goes up and down causing global temperatures to fluctuate up and down. El Nino and La Nina oscillations in the South Pacific Ocean also lead to relatively warm years (El Nino) and cool years (La Nina). The years 1998 and 2005 are interesting to compare. Depending upon the method used to analyze the temperature data, scientists have concluded that either both years tied for the warmest temperatures on record or 2005 was slightly warmer (see here or here). That 1998 was unusually warm is not surprising. It was a year with an unusually strong El Nino and with the sun close to its 11-year maximum. By comparison, the sun in 2005 was near the minimum in its cycle, and the year began with a weak El Nino that dissipated by late spring. A reasonable explanation for 2005 being as warm or warmer than 1998 without the benefit of a solar maximum or strong El Nino includes warming from greenhouse gases. Global warming from greenhouse gases does not occur in a vacuum; it occurs simultaneously with other factors that affect global temperatures like solar variations and El Nino/La Nina oscillations. As I discussed in my previous posts in this series, these other factors can cause short-term ups and downs in global temperatures. But the question for global warming is whether they cause a net temperature change. To determine that, we filter out the short-term fluctuations by using longer term averages (such as the 5-year averages shown in the graphic), and when we do, the upward trend in global temperatures comes through loud and clear –- take a look at the green diamonds.
Learn to read.
The warming of the globe does not match the cyclic nature of the ocean currents' temperature fluctuations. The land and the oceans are both warming at the surface even though the temperature of the ocean currents remains cyclic.
What happens in your deranged little denier cult fantasy world has no connection to the reality the rest of world inhabits. Including these imaginary "reversals" you prattle about. You are obviously impervious to the facts and you will probably cling to your myths and fantasies long after they make you a laughingstock among all who know you. As your posts have made you here, you poor, poor, deluded retard.
Getting back to reality and the topic of this thread, here is come material from a post I made on another thread that deals with the topic of this thread.
Global Warming Since 1998
Duke University
by Dr. Bill Chameides - Duke University Professor, Dean of Duke University Nicholas School of the Environment, Member of the National Academy of Sciences, Fellow of the American Geophysical Union .
October 28th, 2008
(excerpts)
You don’t have to search too hard to find a skeptic’s blog proclaiming that global warming “stopped” in 1998. Oh happy day if it were true, but sadly it is not. Why do I say this? I’ve looked at the data. Take a look at the graphic below, which shows the average global temperatures from 1990 to the present. The green diamonds show the 5-year averages for the periods from 1988–1992, 1993–1997, 1998–2002, and 2003–2007. Each successive diamond appears at a higher temperature than the one before. In other words, global temperatures have been increasing over the past 15+ years — global warming has not stopped.
Global temperature trends since 1990. Solid line with small dots indicate the annual averages. The green diamonds indicate the 5-year averages. Data taken from the Carbon Dioxide Information Analysis Center at the Oak Ridge National Laboratory: CDIAC Temperature Data Sets
If you look at the temperatures in the graphic year by year, it’s easy to see why someone might think that the warming has stopped. After all, there was a huge temperature maximum in 1998. Since then, only 2005 [and now 2010] had average temperatures equal to or perhaps slightly greater than those in 1998. Eyeballing temperatures from 1998 onward might lead to the inference that temperatures have not increased at all -– that global warming has stopped. But wait. If you do the same eyeballing exercise starting in 1999 or 1996 you would conclude that there has been a rapid increase in temperatures. Moreover, if you were back in 1992 or 1993 and had done the same eyeballing exercise back to 1990, you would have concluded that global warming had stopped; and you would have been wrong. So what’s the problem? It comes from a confusion between inter-annual and short-term temperature changes and the longer-term changes in temperatures that are relevant to the issue of climate change on decadal time scales.
There are any number of factors that cause global temperatures to rise and fall. Solar activity is one –- as the sun goes through its 11-year sunspot cycle, solar radiation goes up and down causing global temperatures to fluctuate up and down. El Nino and La Nina oscillations in the South Pacific Ocean also lead to relatively warm years (El Nino) and cool years (La Nina). The years 1998 and 2005 are interesting to compare. Depending upon the method used to analyze the temperature data, scientists have concluded that either both years tied for the warmest temperatures on record or 2005 was slightly warmer (see here or here). That 1998 was unusually warm is not surprising. It was a year with an unusually strong El Nino and with the sun close to its 11-year maximum. By comparison, the sun in 2005 was near the minimum in its cycle, and the year began with a weak El Nino that dissipated by late spring. A reasonable explanation for 2005 being as warm or warmer than 1998 without the benefit of a solar maximum or strong El Nino includes warming from greenhouse gases. Global warming from greenhouse gases does not occur in a vacuum; it occurs simultaneously with other factors that affect global temperatures like solar variations and El Nino/La Nina oscillations. As I discussed in my previous posts in this series, these other factors can cause short-term ups and downs in global temperatures. But the question for global warming is whether they cause a net temperature change. To determine that, we filter out the short-term fluctuations by using longer term averages (such as the 5-year averages shown in the graphic), and when we do, the upward trend in global temperatures comes through loud and clear –- take a look at the green diamonds.
When deniers cannot rebut, they deflect.Learn to read.
The warming of the globe does not match the cyclic nature of the ocean currents' temperature fluctuations. The land and the oceans are both warming at the surface even though the temperature of the ocean currents remains cyclic.
So there's no "Global" in global warming, that's why it's now called "Climate change"
OK.....LOLOLOLOLOLOL....thanks for answering my question in your own unique way....it seems you really are that retarded and that clueless about what is causing the currently accumulating climate changes that are being observed......unbelievable.....LOLOLOL....
When deniers cannot rebut, they deflect.Learn to read.
The warming of the globe does not match the cyclic nature of the ocean currents' temperature fluctuations. The land and the oceans are both warming at the surface even though the temperature of the ocean currents remains cyclic.
So there's no "Global" in global warming, that's why it's now called "Climate change"
The surface on the land and oceans is warming and to you that means there is nothing "global" about the land and oceans.
That's why deniers are now called "Misinformed Voters."
There has been no cooling cycle the last 16 years. In fact there has been no cooling cycle over the last 100 years even though during that 100 years there has been 2 warming cycles.Except for the last 16 years you mean....When deniers cannot rebut, they deflect.
The surface on the land and oceans is warming and to you that means there is nothing "global" about the land and oceans.
That's why deniers are now called "Misinformed Voters."
Deniers: they ignore EVERYTHING.
