Those of us in the reality-based community knew this was going to happen soon: as the moderate-strength La Niña ended last winter, the chance for record warmth to again be recorded would be higher. Not only has the La Niña ended, but an El Niño has begun to take its place. Why is that important? Because the La Niña was masking the underlying warming trend many scientists thought was still going on. Climate change deniers jumped on their talking-point bandwagon and spent the better part of the past 18 months trying to convince everybody they could that the globe was actually cooling! This despite the fact that globally averaged temperatures remained in the top-10 of recorded history over the past two years. Now that the La Niña has subsided, that warming trend has again become more obvious.
Here is the bottom-line: global sea-surface temperatures (SSTs) in July set an all-time record, breaking the old record set back in 1998 … during the extreme El Niño event of 1997-98. Read that again carefully: July 2009 SSTs were warmer than the record SSTs recorded during the extreme El Niño event of July 1998. Global SSTs haven’t been this warm in all of recorded history. That’s not something that would happen if human-forced climate change didn’t exist. Remember, the solar cycle today remains at a minimum that has lasted longer than previous minimums, so it isn’t that the sun is causing this record value.
Just as importantly, the same thing happened last month: June 2009 SSTs were the warmest on record. Two months a trend does not make, but two consecutive months of record temperatures indicates that something is likely occurring. You should expect to hear more about temperature records being tied or broken the rest of this year and into the beginning of 2010 as the El Niño adds its weight to global temperatures.
This has an effect; it isn’t just an interesting statistic to point to. Adding heat to materials causes them to expand. So without any melting of land-based glaciers, ocean levels will rise due to the increased heat now in them. Thermal expansion of the world’s oceans is a result of our forcing heat-trapping gases into the atmosphere.