Is man alone responsible for global warming?

Answer 1

No. In fact, mankind has little, if any, responsibility for global warming. The alternate answer No, man is not only responsible for global warming (0.1% contribution) he is also responsible for a great many other things (industry, health, wealth, law, peace, happiness etc) including the development of the instruments by which global warming is measured. Not Even the alarmist IPCC admits that some part of the warming experienced over the last 150 years is due to the ongoing recovery from the Little Ice Age. Being alarmists, however, they obviously put the lion's share of the blame on humans. But the point is, no credible scientists puts 100% of the blame on humanity. They admit they don't fully understand what's going on.

Let's be real here.

There are a few things that both sides agree on:

1. The current warming cycle appears to have started 6000 years ago.

2. Man produces about 0.28% of all Green house gases and less then 6% of the CO2

3. No warming has been noted for a decade.

4. CO2 has always (and is currently) followed temperature and never led it. (Temp causes CO2 changes not CO2 causing temp)

5. The vast bulk of the Carbon on the planet is now contained in limestone and thus will never be part of our atmosphere again. No matter what, we can never have highs that were part of our past.

6. The planet has warmed 11 degrees in the past 6000 years and almost all of that (save for 0.6 degrees) is prior to burning our first piece of wood.

7. Total CO2 levels in our atmosphere have reached 0.03% (up 0.007%) over the life of man. Man may not be entirely alone in causing the rise in average global temperatures since the beginning of the Industrial Age, but the scientific consensus is that he is substantially responsible for that increase.

Let's get real here. The following are facts:

1. Around 5000 BCE (7,000 years ago), global average temperatures reached a level little different to those experienced at the beginning of the twentieth century. Sea levels, having risen around 120-130 metres since the last Ice Age, were now consistent with modern levels. When it suits skeptics, they claim that the Medieval Warm Period was even warmer than it is today, but when it suits otherwise, they claim that there has been a warming trend for thousands of years. Scientists, on the other hand, say that present average temperatures are the highest they have been for at least two thousand years, and very possibly a million years.

2. Man produces nearly 30 billion metric tons of carbon dioxide annually from the use of fossil fuels, in addition to the emissions from cement manufacture and deforestation. This is not to be sneezed at.

3. The past decade was the warmest since instrumental measurement began in 1850, and the ten warmest years since 1850 have now all occurred since 1998.

4. A simplistic view is that carbon dioxide levels never drive temperature rises. This view proves that "a little knowledge is a dangerous thing" (Ovid, if I remember).

5. Man is responsible for the release of carbon dioxide from limestone, as a byproduct of cement manufacture. We can not rely on this remaining sequestered forever if we choose to make cement.

6. The lowest temperatures reached on a global average basis during the last Ice Age was about 4.6 degrees Celsius below twentieth century temperatures, and temperatures have risen by 0.75 degrees Celsius since the Industrial Revolution. It is an old habit of climate skeptics to mix Fahrenheit (since the Ice Ages) and Celsius (since the Industrial Revolution) to minimize the apparent human contribution.

7. Although carbon dioxide concentrations are still only 390 parts per million of the atmosphere (up from the long-term average of 260-280 parts per million), this is not cause for complacency. Carbon dioxide is an effective greenhouse gas at these concentrations.

Answer 2

Here we are speaking of the increase in average global temperatures since the beginning of the Industrial Age. The rise in temperatures is consistent with the rise in greenhouse gas levels, which in turn is consistent with carbon dioxide emissions from human activities. However climate scientists cautiously say that human activities are "substantially" the cause of this global warming, leaving open the possibility that a much less substantial contribution could be found from natural causes. Thus the cautious answer could be that humans are substantially, if not completely, responsible for global warming that has occurred during the Industrial Age.