(If you did not read my last entry, read it first, please.)
So, I have given an example of the level of controversy surrounding the Big Bang to try and illustrate varying degrees of scientific controversy. Out of tens of thousands of professional astronomers, fewer than 100 would claim that the Big Bang Theory is controversial. Many more would question the idea of inflation, and most would say that the details of the theory of inflation are controversial. And almost every astronomer would say that what came before Inflation is controversial.
Now let's look closer to home. Recently, global warming has been in the news again. Al Gore's new movie claims it is true, while large petroleum corporations strongly argue that global warming is controversial. So, from a scientific standpoint, is global warming controversial?
I recently learned of a study published in the journal Science. This is a highly-respected journal read by most scientists in the United States. In December 2004, scientists writing in the journal did a search for all articles published between 1993 and 2003 in peer-reviewed journals containing the words "climate change" in the abstract or keywords. What does this mean? It means that they searched for articles claiming to be about climate change, and that these articles had all been reviewed by another professional scientists with expertise in the field.
The search found 928 articles, or an average of seven per month. Of those, not a single article disagreed with the view that global warming is occuring and is due to greenhouse gases being released by human activity. Now, to be fair, 25% of these articles are about past climate change (like Ice Ages) or about methods of detecting climate change, and take no stand (for or against) current climate change. But still, this leaves nearly 700 articles by professional scientists stating that humans are causing global warmingm and not a single article suggesting otherwise. Think about it -- this is 100% agreement! How often does this happen?
Some of you might claim that scientists are suppressing opposing viewpoints. But let's go back to astronomy and the Big Bang. Remember that all but a few astronomers strongly believe in the Big Bang. Despite this, we still allow articles by those few astronomers to be published in our professional journals. It would be easy for us to suppress these viewpoints, but we do not. The same is true in other areas of science. Dissent, controversy, and the resolution of these differences is what propels science forward.
When I heard this statistic from Science Magazine, I was astounded. I've never heard of 100% agreement on any issue, though some (like the Big Bang Theory and the Theory of Evolution) come close. Not even 100% of astronomers believe in Albert Einstein's General Theory of Relativity!
So, it is time to face up to the truth. According to people who have spent their lives understanding the Earth's climate and how it changes, the Earth is warming up, and it is due to humans. It is no longer time to ask if global warming is occuring, it is time to ask what we are going to do about it!