Answer 1:
The sun is getting fainter right now, and we
are noticing that the Earth is cooling off in the
last couple of years in response. You are
absolutely right to be thinking about global
warming and sunspots. In addition to the 11-year
cycle, there also appears to be a 2-300 year cycle
as well. This longer-term cycle was probably
responsible for the Little Ice Age, a cold period
during the 1700s. It is very possible that much of
the observed global warming may in fact be just
the sun getting brighter over the past two hundred
years. However, things are also happening that
indicate that climate is doing things that it
hasn't for many thousands of years - the glaciers
on Kilimanjaro disappearing, for example (those
glaciers are many thousands of years old). Still,
how much of that is our doing, and how much of it
is natural? I think I can confidently say that
nobody really knows yet. |