Yes, We Know Global Warming is Happening

By S. T., on October 15th, 2009

Today is writers’ action day on Climate Change. That means the subject will finally get close to the attention it deserves by people who write online!

Yet no matter how much attention the issue of climate change gets, there are skeptics and deniers, and some of them are very loud. They even protest climate legislation during things they call “tea parties”. But we know climate change is real, and we know that it’s happening now. It’s not some vague, undefined thing that will happen far into the future. There are measurable effects of it today. These effects will increase in the future. We know climate change is happening because of measurable data in the air temperatures, ocean temperatures and other measurements. Temperatures have been rising steadily, with a few flucturations here and there, (some lasting a decade or more) for about 200 years or more, in large part due to human activity. Some natural factors are also at play of course. We can’t do anything about them, but we can change the activities that we are responsible for. Those activities consist mainly of burning fossil fuels and other things that emit greenhouse gases into the atmosphere, changing our climate. Why is that so hard for some people to believe?*

RealClimate is a great website for serious climate science presented by scientists. They have discussed proof of global warming for years. They have also discussed the deniers concerns and the latest rumor or meme that we are “cooling”. (No, there is no “global cooling” but there are weather fluctuations). The Arctic is warming faster than anywhere else and continues to do so. Greenland is virtually melting. The permafrost is melting. RealClimate, as they say, has discussed this topic repeatedly, and then goes on to address the perceived “pause.” Basically, they remind us that people should not confuse long term climate change with short term weather variability, which many people do to prove a false claim.

“It is highly questionable whether this “pause” is even real. It does show up to some extent (no cooling, but reduced 10-year warming trend) in the Hadley Center data, but it does not show in the GISS data, see Figure 1. There, the past ten 10-year trends (i.e. 1990-1999, 1991-2000 and so on) have all been between 0.17 and 0.34 ºC per decade, close to or above the expected anthropogenic trend, with the most recent one (1999-2008) equal to 0.19 ºC per decade – just as predicted by IPCC as response to anthropogenic forcing.”

The following is also important. The bottom line: there are more than enough observations and data to convincingly present a case for global warming, and this has been the case for a long time. Warming measurements are following the predicted path for warming models, despite some blips along the way.

“It is noteworthy in this context that despite the record low in the brightness of the sun over the past three years (it’s been at its faintest since beginning of satellite measurements in the 1970s), a number of warming records have been broken during this time. March 2008 saw the warmest global land temperature of any March ever recorded in the past 130 years. June and August 2009 saw the warmest land and ocean temperatures in the Southern Hemisphere ever recorded for those months. The global ocean surface temperatures in 2009 broke all previous records for three consecutive months: June, July and August. The years 2007, 2008 and 2009 had the lowest summer Arctic sea ice cover ever recorded, and in 2008 for the first time in living memory the Northwest Passage and the Northeast Passage were simultaneously ice-free. This feat was repeated in 2009. Every single year of this century (2001-2008) has been warmer than all years of the 20th Century except 1998 (which sticks out well above the trend line due to a strong El Niño event).

The bottom line is: the observed warming over the last decade is 100% consistent with the expected anthropogenic warming trend of 0.2 ºC per decade, superimposed with short-term natural variability.

It has just been predicted that the weather this winter will be warmer than usual in the United States. Where I live (Minnesota) this has been the gradual trend for the last 8 or so years, with the exception of last winter, which was awfully cold. But in general, winters here are obviously warming up. Short term warming like that does not “prove” anything, though.

In some parts of the United States, the weather is cooler than usual. That also proves nothing because it’s too short a time period. Because something happens in one spot in the United States, or in several spots, does not mean that global warming has stopped. But if all of the north is showing trends of warming over decades, which has happened, that is probably what is happening.

Some skeptics have a problem with “climate models”. OK.

The planet is heating up, thanks to human-generated emissions of greenhouse gases. As a new NOAA-led study, “An observationally based energy balance for the Earth since 1950” (subs. req’d, release here) concluded:

[S]ince 1950, the planet released about 20 percent of the warming influence of heat-trapping greenhouse gases to outer space as infrared energy. Volcanic emissions lingering in the stratosphere offset about 20 percent of the heating by bouncing solar radiation back to space before it reached the surface. Cooling from the lower-atmosphere aerosols produced by humans balanced 50 percent of the heating. Only the remaining 10 percent of greenhouse-gas warming actually went into heating the Earth, and almost all of it went into the ocean.

Note that this Journal of Geophysical Research-Atmospheres study was done “without using global climate models.”

Figure 1: “Total Earth Heat Content [anomaly] from 1950 (Murphy et al. 2009). Ocean data taken from Domingues et al 2008.”

That figure comes from the first of two posts by the terrific website Skeptical Science, which I repost below. Skeptical Science is an excellent, well-organized site to send convincible people for a shredding of the standard, long-debunked denier talking points.

Borrowed from Climate Progress.org

One way we know global warming is continuing is that the ocean temperatures have steadily continued to rise. Weather affects the air temperature and storms, but not so much the ocean temperature. (See: “2009 Ocean surfaces have warmest summer on record, US report finds)

Some weather cycles have kept some areas of the world cooler in air temperature, but that’s regional. Any cool temperature, though, brings out the deniers.

It’s also important for people to know that just because they read something repeated over and over again online doesn’t make it true, because as the climate/energy/jobs legislation is reaching a point of debate in Congress, the lobbyists representing the energy and oil companies are stepping up their efforts to spread lies. They are employing people to spread this misinformation and muddy the waters. What they want more than anything is for the public to doubt that there is any risk and that will be enough for many people to oppose any legislation.

Don’t miss this story about the deliberate misinformation campaigns too: Industry Ignored Its Scientists on Climate

“…a document filed in a federal lawsuit demonstrates that even as the coalition worked to sway opinion, its own scientific and technical experts were advising that the science backing the role of greenhouse gases in global warming could not be refuted.

“The scientific basis for the Greenhouse Effect and the potential impact of human emissions of greenhouse gases such as CO2 on climate is well established and cannot be denied,” the experts wrote in an internal report compiled for the coalition in 1995.

The coalition was financed by fees from large corporations and trade groups representing the oil, coal and auto industries, among others. In 1997, the year an international climate agreement that came to be known as the Kyoto Protocol was negotiated, its budget totaled $1.68 million, according to tax records obtained by environmental groups.”

Conclusion: Climate change and global warming are unfortunately very real, but there are a lot of people who don’t want the public to know this.

For more information on the psychology and more on deniers and skeptics, see: (thanks for this list to greenfyre)

The Psychology of Climate Denial