What is the greenhouse effect, and is it affecting our climate?
The greenhouse effect is unquestionably real and helps to regulate the temperature of our planet. It is essential for life on Earth and is one of Earth's natural processes. It is the result of heat absorption by certain gases in the atmosphere ...
"Certain gases?" Any gas blanket produces a greenhouse effect.
Are greenhouse gases increasing?
Human activity has been increasing the concentration of greenhouse gases in the atmosphere (mostly carbon dioxide from combustion of coal, oil, and gas; plus a few other trace gases). There is no scientific debate on this point.
Wrong again;
if one wishes to assert that there is
no net flux between the biosphere and atmosphere, and
no net flux between the hydrosphere and atmosphere, one may conclude that fossil fuel use is the main contributor to CO
2 concentration increase in the atmosphere. There are
no measurements of the other two fluxes; the large exchange rates among biosphere, hydrosphere, and atmosphere effectively prevent them. Is there any reason to assert that they are "net zeros?" No.
Is the climate warming?
Yes. Global surface temperatures have increased about 0.6°C (plus or minus 0.2°C) since the late-19th century ...
Covered this earlier.
Is the hydrological cycle (evaporation and precipitation) changing?
Their answer speaks for itself --- three paragraphs of "waffle-speak" (suggest, perhaps, appears) to the effect that they have no idea.
Is the atmospheric/oceanic circulation changing?
When isn't it? Irrelevant.
Is the climate becoming more variable or extreme?
Seven paragraphs of "waffle-speak."
How important are these changes in a longer-term context?
"Longer-term" is limited to a few thousand years as far as the data they trust; "Based on the incomplete evidence available, the projected change of 3 to 7°F (1.5 - 4°C) over the next century would be unprecedented in comparison with the best available records from the last several thousand years," translates to, "Gee, if this wild-assed guess of ours means anything, this would be something no one's seen before," that is, nothing.
Well, "DUH." We got out of an ice age 10-15ka back --- aquifers were full, and they've been relaxing --- 1-2 mm/a current rate is consistent with the 3ka time constant hydrologists use for a "global average" recharge/discharge time for aquifers.
Can the observed changes be explained by natural variability, including changes in solar output?
Let's use their own PR department's "waffle-speak" again, "However, our understanding of the indirect effects of changes in solar output and feedbacks in the climate system is minimal. There is much need to refine our understanding of key natural forcing mechanisms of the climate, including solar irradiance changes, in order to reduce uncertainty in our projections of future climate change."
"Do it yourself?" It's been shot, skinned, cut, dried, stuffed, mounted, and gathering dust in libraries for nearly a century; it's "done" science, and it was "done" by "experts" who had no political, funding, or publish or perish axes to grind.
