Global Climate Change?

Question

It is undisputed that the temperature has been rising, but it is also undisputed that the earth goes through cycles and has gotten this warm and according to some data even warmer in the past. I have seen many graphs that show data from millions of years ago that indicate extremely high temperatures in correlation with low amounts of carbon dioxide. Obviously that is not the case now. I would like to know then, if in the past there has been cyclical "global warming" unrelated to the amount of CO2 in the atmosphere, is the fact that humans have significantly increased the amount of CO2 in the atmosphere a legitimate argument that humans have caused global warming? If you are an extreme environmentalist please don't get defensive, I just want to know the facts. I can't decide if I truly believe that humans are causing global climate change.

Answer 1

This chart alone shows the correlation between CO2 and the climate change cycle.  http://www.epa.gov/climatechange/science...

There is no doubt that greenhouse gases, especially CO2, lead to increased temperatures, and man has greatly increased the amount of atmospheric CO2.

EDIT: I would be interested to see those graphs that show high temperatures in correlation with low CO2.  I have never seen one myself.

Answer 2

You can see a graph of atmospheric CO2 vs. global temperature on geologic time scales on this website:

http://www.geocraft.com/WVFossils/Carbon...

As you can see, there haven't really been any periods of high temperatures and low CO2 levels.  There are of course other causes of global warming other than CO2 and other greenhouse gases.  However, we know those causes are not the cause of the current warming.  See the link below for an explanation of how we know this.

Answer 3

Global warming -- a gradual increase in planet-wide temperatures -- is now well documented and accepted by scientists as fact. A panel convened by the U.S National Research Council, the nation's premier science policy body, in June 2006 voiced a "high level of confidence" that Earth is the hottest it has been in at least 400 years, and possibly even the last 2,000 years. Studies indicate that the average global surface temperature has increased by approximately 0.5-1.0°F (0.3-0.6°C) over the last century. This is the largest increase in surface temperature in the last 1,000 years and scientists are predicting an even greater increase over this century. This warming is largely attributed to the increase of greenhouse gases (primarily carbon dioxide and methane) in the Earth's upper atmosphere caused by human burning of fossil fuels, industrial, farming, and deforestation activities.

Average global temperatures may increase by 1.4-5.8ºC (that's 2.5 - 10.4º F) by the end of the 21st century. Although the numbers sound small, they can trigger significant changes in climate. (The difference between global temperatures during an Ice Age and an ice-free period is only about 5ºC.) Besides resulting in more hot days, many scientists believe an increase in temperatures may lead to changes in precipitation and weather patterns. Warmer ocean water may result in more intense and frequent tropical storms and hurricanes. Sea levels are also expected to increase by 0.09 - 0.88 m. in the next century, mainly from melting glaciers and expanding seawater . Global warming may also affect wildlife and species that cannot survive in warmer environments may become extinct. Finally, human health is also at stake, as global warming may result in the spreading of certain diseases such as malaria, the flooding of major cities, a greater risk of heat stroke for individuals, and poor air quality.

Climate change is very likely having an impact now on our planet and its life, according to the latest installment of a report published by the Intergovernmental Panel on Climate Change (IPCC). And the future problems caused by rising seas, growing deserts, and more frequent droughts all look set to affect the developing world more than rich countries, they add. The report is the second chapter of the IPCC's Fourth Assessment -- the most comprehensive summary yet of research into the causes and effects of climate change. To read more, visit Effects of climate change tallied up.

Factors

Greenhouse Gases

The increase in greenhouse gases caused by human activity is often cited as one of the major causes of global warming. These greenhouse gases reabsorb heat reflected from the Earth's surface, thus trapping the heat in our atmosphere. This natural process is essential for life on Earth because it plays an important role in regulating the Earth's temperature. However, over the last several hundred years, humans have been artificially increasing the concentration of these gases, mainly carbon dioxide and methane in the Earth's atmosphere. These gases build up and prevent additional thermal radiation from leaving the Earth, thereby trapping excess heat.

Solar Variability & Global Warming

Some uncertainty remains about the role of natural variations in causing climate change. Solar variability certainly plays a minor role, but it looks like only a quarter of the recent variations can be attributed to the Sun. At most. During the initial discovery period of global warming, the magnitude of the influence of increased activity on the Sun was not well determined.

Solar irradiance changes have been measured reliably by satellites for only 30 years. These precise observations show changes of a few tenths of a percent that depend on the level of activity in the 11-year solar cycle. Changes over longer periods must be inferred from other sources. Estimates of earlier variations are important for calibrating the climate models. While a component of recent global warming may have been caused by the increased solar activity of the last solar cycle, that component was very small compared to the effects of additional greenhouse gases. According to a NASA Goddard Institute for Space Studies (GISS) press release, "...the solar increases do not have the ability to cause large global temperature increases...greenhouse gases are indeed playing the dominant role..." The Sun is once again less bright as we approach solar minimum, yet global warming continues.

HUMANS MADE THIS MESS AND WE ARE THE ONLY ONES WHO CAN CLEAN IT UP! SAVE THE WORLD! SEA LEVELS WILL RISE, MORE INTENSE HURRICANES, AND DIRTY AIR! RECYCLE: PAPER, PLASTIC, AND BOTTLES! *YES WE CAN STOP GLOBAL WARMING!*

Answer 4

At last, a cogent question from someone who has taken the time to do just a little research instead of blindly believing what Al Gore and his liberal cronies are saying.  Wow!  I'm impressed!

Answer 5

Before we know if global warming is bad we have to know what the 'ideal' temperature is for the earth. A temp at which all things can live in health. For example, we know the ideal body temp is 98.6. Higher than that and a human is running hot, or a fever. Over the life of the earth, we have to find what the ideal temp is before we can say the warming of the globe is bad.