Officially there is no global warming (NOAA ,October 8, 2008, National Weather Service JetStream - Online School for Weather) http://www.srh.noaa.gov/srh/jetstream/atmos/ll_gas.htm [Broken] quote It has been thought that an increase in carbon dioxide will lead to global warming. While carbon dioxide in the atmosphere has been increasing over the past 100 years, there is no evidence that it is causing an increase in global temperatures. In 1997, NASA reported global temperature measurements of the Earth's lower atmosphere obtained from satellites revealed no definitive warming trend over the past two decades. In fact, the trend appeared to be a decrease in actual temperature. In 2007, NASA data showed that one-half of the ten warmest years occurred in the 1930's with 1934 (tied with 2006) as the warmest years on record. (NASA data October 23, 2007 from http://data.giss.nasa.gov/gistemp/graphs/Fig.D.txt [Broken]) The 1930s through the 1950s were clearly warmer than the 1960s and 1970s. If carbon dioxide had been the cause then the warmest years would have understandably been in the most recent years. But that is not the case. The largest differences in the satellite temperature data were not from any man-made activity, but from natural phenomena such as large volcanic eruptions from Mt. Pinatubo, and from El Niño. The behavior of the atmosphere is extremely complex. Therefore, discovering the validity of global warming is complex as well. How much effect will the increase in carbon dioxide will have is unclear or even if we recognize the effects of any increase. end-quote El Niño is a consequence, not a cause, and in that web page the reference to Venus is absolutely inappropriate and misleading. Yes, the clime is always changing, as always. Lets talk about other models?