Birch Aquarium has a new exhibit, "Feeling the Heat: The Climate
Challenge."
The exhibit draws on the considerable scientific expertise of UC San
Diego's
Scripps Institution of Oceanography. The exhibit, like nearly
everything else
today, has a website. It's URL is:
http://aquarium.ucsd.edu/Exhibits/Feeling_the_Heat/ (Who's computer is this?)

One interesting page on that website is:
http://aquarium.ucsd.edu/climate/Climate_Change_FAQ/ (Who's computer is this?)

Climate Change FAQ
QUESTION: If climate changes naturally over time, why isn't the
current warming just another natural cycle?
ANSWER: Earth's climate does change naturally, but the current warming
is not natural. Known natural causes of warming, such as the sun, have
been constant in the past 30 years, so they cannot explain the warming
of the past 30 years. The pattern of the current warming is also
highly unnatural. For example, it is warming more at night than during
the day; this is expected for CO2-caused heat trapping, because CO2
works at night, whereas natural warming would be more in the day. A
long list of similar patterns (a "fingerprint" of human-caused
warming) proves conclusively that the warming isn't natural.

QUESTION: It snowed last winter! There can't be global warming! (Or:
My neighborhood is cooling! There can't be global warming!)
ANSWER: The warming trend is superimposed on significant natural
variability.

QUESTION: Scientists can't predict the weather next week. Why do they
think they can predict the climate in 50 years?
ANSWER: If you flip a coin, you can't predict whether it will land as
heads or tails, but you can be absolutely confident that you have a
50% chance of heads and a 50% chance of tails. Predicting climate is
predicting the probability of events, not the actual occurrence of
events. Global warming is a forced problem. Imagine loaded dice, and
that every week you put more loading weight in them. The loading
factor here is CO2. More and more of it every year, known for 100
years to warm the planet.

QUESTION: Climate scientists can't predict when we will pass an
irreversible threshold into catastrophe, whether it's 10 years from
now or 100 years from now, so why believe them at all?
ANSWER: It has been known since 1869 that CO2 traps heat. This is
settled physics. It has been shown beyond a shadow of doubt that
humans have increased CO2 in the atmosphere by 30% in the last 150
years. Basic physics plus remedial math, and the rest is details. It
is true that climate scientists can't predict when irreversible
thresholds will be crossed, because we don t yet fully understand the
behavior of Earth's complex climate system. But that does not mean
that the basic understanding that CO2 causes warming is flawed. To use
a medical analogy, just because your doctor can't tell you the precise
date and time that you will have a heart attack doesn't mean you
should ignore his advice and keep on eating fatty, high-calorie food.
Medical science is imperfect, just like climate science.

QUESTION: Scientists disagree. We don't know the science well enough
yet, so why should we do anything?
ANSWER: Actually, there is strong scientific consensus on the reality
of human-caused climate change. See the consensus/position statements
of: - National Academy of Sciences - Intergovernmental Panel on
Climate Change (IPCC) - American Geophysical Union (AGU) - American
Meteorological Society (AMS) - American Association for the
Advancement of Science (AAAS) Oreskes (Science, 2004) analyzed all
abstracts in refereed scientific publications from 1993-2003 with the
keywords "global climate change" (928 papers). None disagreed with the
consensus position that human activities are causing the current
warming.

QUESTION: Climate change and its effects are too uncertain. Why should
we do anything?
ANSWER: Even the most conservative models show significant disruption.
All decisions are made against a background of uncertainty. While it's
true that scientists can't completely predict the future, that doesn't
mean we should give up all attempts at planning according to our best
knowledge.

QUESTION: Since it's snowing more on land-based ice sheets due to the
warming, wouldn't this make sea level fall rather than rise?
ANSWER: It is indeed snowing more than it used to in the interiors of
Antarctica and Greenland, because warmer air holds more moisture, but
the mass gain in the interiors is more than offset by the mass loss
around the margins due to glaciers sliding faster into the ocean in
response to warming. So the net change is one of mass loss from the
ice sheets, which is causing sea level to rise. This is responsible
for about half of the observed 3 mm rise per year. The mass loss of
Antarctica has been recently verified by the GRACE gravity satellite,
which showed that gravity over Antarctica is weakening due to the loss
of mass.

QUESTION: Isn't the urban heat island effect (that elevates
temperatures in large cities relative to rural areas) responsible for
the measured increase in global temperature?
ANSWER: There is no urban heat island effect in the oceans, which
cover nearly 3/4 of Earth's surface, yet sea surface and deep ocean
temperatures are also increasing, consistent with what's occurring on
land.

Thanks to Scripps researchers Jeff Severinghaus, Richard Somerville,
and Dave Pierce for providing answers to these questions.