Two significant factors that contribute to the amount of energy the Earth receives are solar irradiance and how our planet collects it. The last article in this series discussed the solar aspect and how it can affect the Earth and other planetary bodies. The other half of the equation is how Earth is able to absorb and reflect solar radiation. There are many variables that contribute to our planet’s albedo – or, its reflectivity. Despite the fact that this is not openly discussed by the anthropogenic global warming (AGW) proponents, it plays a very critical role in determining our climate.

In a very simplistic but still accurate sense, there are only two factors that determine our global surface temperature – how much energy the Earth receives and how much is radiated back into space. This article will focus on the former element of the equation.

When the Earth’s albedo changes, it affects the way energy is both absorbed and reflected. The percentage of radiation that is reflected by our planet is around 30% on average, which means about 70% is retained and becomes part of our climate system. However, albedo – like nearly all of the other variables that contribute to our climate – is not constant. As clouds change, deserts and ice expand or retreat, and vegetation increases or decreases, the Earth’s albedo is affected. How much each of these contributes to the changes is not yet fully understood, and may never be.

We know that long-term changes in absorbed radiation have an effect on global climate. The Milankovitch Cycles show how some of these changes may occur and how they coincide with Earth’s glacial and interglacial periods. These cycles obviously do not change the amount of radiation that is emitted from the Sun. What they do illustrate is how the effects of increased or decreased radiation due to changes in albedo contribute to the Earth’s dramatic shifts in temperature and overall climate. These long-term variations can account for long-term climate shifts, but they cannot account for changes within a span of a few decades or centuries. However, it does prove that albedo is a critical element of our climate process and that it must be thoroughly examined.

At the opposite end of the spectrum, clouds can affect temperatures on a very brief time scale. The difference in temperature between a bright sunny day and an overcast day can be relatively large. Even on an extremely hot day when the Sun is shining, one can experience the cooling effects of a passing cloud above. This natural occurrence can make the temperature feel several degrees cooler, and once it passes, the intense heat returns. In essence, this is what the Earth is constantly doing on a slightly longer time scale. So, it would make sense to try to understand these changes.

Scientists at the Big Bear Solar Observatory in California have been studying the Earth’s albedo with their Earthshine Project. This project was restarted in 1998 with the support of NASA and has since determined that the Earth’s albedo is subject to relatively large fluctuations. The project has also published data that illustrates quite a positive correlation between changes in albedo and the increasing global surface temperatures. From 1986 to 1997, the Earth’s albedo decreased consistently by a total of about ten percent. (A decrease in albedo is often referred to as “global dimming.”) The peak of this change in albedo coincides with one of the warmest years on record – 1998.

Since the year 2000, albedo has slowly begun to increase and temperatures have leveled off in recent years.

The assumed effect from these changes in albedo on the amount of radiative forcing overwhelms the alleged forcing from increased carbon dioxide published in the IPCC’s Fourth Assessment Report. The IPCC estimates that human contributions to carbon dioxide over the last 150 years have resulted in approximately 2.4 Watts per square meter of additional forcing. The chart showing changes in albedo calculated by the scientists of the Earthshine Project indicates a range of over 10 Watts per square meter from 1986 to 1997. This fluctuation represents more than four times the amount of estimated forcing from carbon dioxide over the last one and a half centuries.

This type of research ought to be examined and discussed more thoroughly, even if it does displease the AGW advocates. Yet there’s still more.

One of the main reasons why albedo has changed is due to the varying amount of Earth’s cloud coverage. Scientists with the International Satellite Cloud Climatology Project (ISCCP) have been tracking clouds since 1983. Their research shows a consistent decline in the amount of total cloud coverage from 1987 through 2001. The 1990’s, which fall entirely within this timeframe of decreased cloud coverage, are considered to be the warmest decade on record. Is this a correlation that ought to be completely dismissed?

Another interesting aspect of the ISCCP data is the fact that low level clouds have been decreasing since the mid-1990’s while mid and upper level clouds have been increasing. This is important because thick, low-level clouds have a net cooling effect and thin, higher-level clouds have a net warming effect. With a decrease in the negative forcing and an increase in positive forcing, a net warming effect is the result.

Despite all of this data, climate models are not able to duplicate these effects with any considerable amount of accuracy, making their results completely unreliable.

In addition to the analysis of albedo and the observations of global cloud coverage, there have also been studies about the effects of cosmic rays and their influence on cloud formation. The cosmic rays that reach Earth largely come from the Sun, but they can also originate from outside of our solar system. The changing magnetism of the Sun and the changes of the 11-year solar cycle have an effect on the amount of cosmic rays that penetrate the Earth’s atmosphere. When the Sun’s magnetic field and solar winds increase, the amount of cosmic rays from outside the solar system decrease. Throughout the 20th century, the strength of the Sun’s magnetic field had doubled.

There have been observed correlations in the amount of cosmic rays that find their way into our atmosphere and the amount of low level clouds. There have also been studies that show an apparent 1,500-year solar cycle that affects cosmic ray influx and ocean temperatures. Over the past several years, experiments have been conducted that confirm the effects of cosmic rays on cloud ionization. While these studies and experiments may not fully explain why temperatures have increased over the last few decades, it does shed some light on a subject that is not very well understood in the field of climatology – clouds and their effects on our climate.

As we continue to learn of the studies and experiments that reveal important information about the Earth’s processes and we continue to observe the changes in solar activity, we will better understand how our climate functions as a whole. With the information at hand from the Earthshine Project and the ISCCP, researchers have been able to identify about a 7 Watt per square meter radiative forcing from changes in albedo over the past 25 years. This is equivalent to a change in solar irradiance of approximately 2%, which is twenty times higher than observed natural solar variation, and nearly three times the assumed effects from carbon dioxide over the past 150 years.

From the combined effects of solar irradiance and the changes in the Earth’s albedo, it is very possible that the global temperature changes we have witnessed in the last few decades are due to natural fluctuations of our climate variables and processes. Further research and experimentation into these variables will only improve our understanding of them and how they affect global temperatures. The AGW advocates that refuse to acknowledge this information or try to dismiss it as a non-factor are only causing more scrutiny and criticism of their own beliefs.

It’s in the best interest of all parties to try to achieve a better understanding of the Earth’s albedo and the impact it has on climate changes. With data that demonstrates a very convincing Sun, albedo, and temperature correlation, it wouldn’t hurt to put a little more effort into learning more about the net effects of all three.

*Other articles in the Climate Change Stupidity series:

An Overview of the Global Warming Hypothesis

An Overview of the Global Warming Hypothesis (Part Two)

Great Ball of Fire

The Earth Also Shines

The Carbon Dioxide Scapegoat

Water in the Atmosphere

**For more articles by this author, click here.