Appearing on the March 2 edition of Fox News' Special Report, senior political analyst Brit Hume -- who is not a climate expert -- acknowledged that "[t]here does seem to have been some increase in the average Earth temperature during the last part of the 20th century" and that “there are computer models that say this trend will continue with profound effects on the way we live.” He then asserted that "[t]he problem with these models is that when data from the past have been plugged into them, they have had trouble predicting today's temperatures. The climate alarmists certainly did not foresee the cooling trend of the past decade." As a result, Hume suggested, the Obama administration is being premature when it “press[es] for a so-called cap-and-trade system to curb carbon dioxide emissions.” In fact, according to climate scientists, there has not been a “cooling trend in the past decade”; the global surface temperature data continue to show a long-term upward trend, and a cooling trend would need to last longer than a decade before it could be distinguished from the natural variability in the Earth's global surface temperature. Indeed, Michel Jarraud, secretary general of the World Meteorological Organisation (WMO), recently stated, “The major trend is unmistakably one of warming.”

As Vicky Pope, the head of climate change advice at the U.K. Met Office Hadley Centre, explained in a February 11 Guardian op-ed, the fact that "[i]n the past 10 years the temperature rise has slowed" does not show that global warming has stopped or slowed down, “since natural variations always occur on this timescale.” She continued, “1998 was a record-breaking warm year as long-term man-made warming combined with a naturally occurring strong El Niño. In contrast, 2008 was slightly cooler than previous years partly because of a La Niña. Despite this, it was still the 10th warmest on record.”

Similarly, in a January 11, 2008, post on RealClimate.org, Gavin Schmidt, a climate modeler at the NASA Goddard Institute for Space Studies, wrote that “short term comparisons” of weather and climate are “misguided.” According to Schmidt, “the climate system has enormous amounts of variability on day-to-day, month-to-month, year-to-year and decade-to-decade periods. Much of this variability (once you account for the diurnal cycle and the seasons) is apparently chaotic and unrelated to any external factor -- it is the weather”:

Some aspects of weather are predictable -- the location of mid-latitude storms a few days in advance, the progression of an El Niño event a few months in advance etc, but predictability quickly evaporates due to the extreme sensitivity of the weather to the unavoidable uncertainty in the initial conditions. So for most intents and purposes, the weather component can be thought of as random.

If you are interested in the forced component of the climate -- and many people are -- then you need to assess the size of an expected forced signal relative to the unforced weather 'noise'. Without this, the significance of any observed change is impossible to determine. The signal to noise ratio is actually very sensitive to exactly what climate record (or 'metric') you are looking at, and so whether a signal can be clearly seen will vary enormously across different aspects of the climate.

Schmidt wrote that “if you start to take longer trends, then the uncertainty in the trend estimate approaches the uncertainty in the expected trend, at which point it becomes meaningful to compare them since the 'weather' component has been averaged out. In the global surface temperature record, that happens for trends longer than about 15 years, but for smaller areas with higher noise levels (like Antarctica), the time period can be many decades.”

Moreover, contrary to Hume's assertion, such short-term trends are not inconsistent with climate models' projections of global warming. Addressing an “ill-informed buzz about very short time scale tendencies,” Schmidt wrote in a May 11, 2008, RealClimate post that "[c]laims that a negative observed trend over the last 8 years would be inconsistent with the models cannot be supported. Similar claims that the [Intergovernmental Panel on Climate Change] projection of about 0.2ºC/dec over the next few decades would be falsified with such an observation are equally bogus." Similarly, in analyzing criticisms of climate models, Schmidt wrote in the January 11, 2008, post:

Are people going back to the earliest projections and assessing how good they are? Yes. We've done so here for [NASA Institute for Space Studies director James] Hansen's 1988 projections, [RealClimate contributor] Stefan [Rahmstorf] and colleagues did it for CO2, temperature and sea level projections from IPCC [Third Assessment Report] (Rahmstorf et al, 2007), and IPCC themselves did so in Fig 1.1 of [[AR4]] [Assessment Report 4,] Chapter 1. Each of these analyses show that the longer term temperature trends are indeed what is expected.

More recently, Schmidt stated in a December 16, 2008, post -- after average temperature data for meteorological 2008 became available -- that "[t]here will undoubtedly also be a number of claims made that aren't true; 2008 is not the coolest year this decade (that was 2000), global warming hasn't 'stopped', CO₂ continues to be a greenhouse gas, and such variability is indeed predicted by climate models."

In addition, Hume said global warming activists in Washington, D.C., were “protesting warming temperatures in a city going through its coldest winter in recent memories -- a city in the midst of a snow emergency and sub-freezing temperatures” and that “they were also doing so on a planet that has seen no average warming for the past 10 years. But climate change alarmists are not easily fazed.” As Media Matters for America has repeatedly noted, climate scientists reject the notion that natural weather variations -- such as snowstorms -- provide any evidence for or against the existence of climate change, and scientists have concluded unequivocally that the Earth is warming.

From the March 2 edition of Fox News' Special Report with Bret Baier:

BAIER: Hundreds of demonstrators pressing for laws to curb greenhouse gas emissions descended on a Washington power plant that heats and cools the Capitol today. The activists braved frigid temperatures in a massive snowstorm that pummeled much of the Northeast.

The weather was so bad that House Speaker Nancy Pelosi [D-CA] was forced to cancel her appearance because of flight delays. Lawmakers have tried to clean up the plant, but it still burns coal and accounts for a third of the legislative branch's greenhouse gas emissions.

And now, senior political analyst Brit Hume is here with his thoughts on the meaning of this protest. Hi, Brit.

HUME: Hi, Bret. Well, you have to give those global warming activists credit for pluck. Not only were they were protesting warming temperatures in a city going through its coldest winter in recent memories -- a city in the midst of a snow emergency and sub-freezing temperatures -- they were also doing so on a planet that has seen no average warming for the past 10 years. But climate change alarmists are not easily fazed.

Just the other day, Doctor Steven Chu, the new Obama energy secretary, worried out loud that global warming could wipe out California's farms and vineyards by the end of the century and he feared for that state's cities as well. Now, there does seem to have been some increase in the average Earth temperature during the last part of the 20th century, and there are computer models that say this trend will continue with profound effects on the way we live.

The problem with these models is that when data from the past have been plugged into them, they have had trouble predicting today's temperatures. The climate alarmists certainly did not foresee the cooling trend of the past decade. No matter.

The Obama administration is pressing for a so-called cap-and-trade system to curb carbon dioxide emissions by, in effect, taxing them. Even the administration agrees that the public will end up paying for this in the form of higher fuel prices. That may not help an economy in the midst of an acute recession, but perhaps it will make Doctor Chu feel better about California -- Bret.

BAIER: So, Brit, what is the science saying today?

HUME: Well, the science is saying a lot of things, but the thing you should listen for is when leading scientists say that there is scientific fact concerning man-made global warming. What we've had instead is something called scientific consensus, which I guess is what you have when you don't have fact. And of course science is about fact.

So what you basically have is a widely held opinion -- though not universally held -- that says we've got a global warming emergency and it's caused by man. That's a small thing, I would think, on which to base a massive change in the way we order our economies and our lives -- a huge change on something that is not yet a fact.

BAIER: All right, Brit. Thanks.