The way I look at it, this question isn''t a complicated one in science. We aren't talking about predicting which way some theoretical but undetectable sub-nuclear particle will spin or whatever. All you have to do to understand the forcing effect of carbon dioxide is measure the amount of heat radiation that penetrates a given concentration of CO2 in the laboratory. These experiments have been carried out and repeated for many decades. That higher concentrations of CO2 trap more heat is very well known and seems almost undisputed. Further, it is a matter of simple geometry to quantify how much atmosphere there is, and simple accounting to know how much gas human activity adds to the air. Thus estimating the effect we have on how much CO2 is in the air is a matter of long division, not some advanced differential equations that few people will ever grasp. So to answer whether humans cause global warming is, in my personal opinion, rather elementary.
Far more complex and controversial, is how this increase in CO2 interacts with the Earth's climate and weather systems, and could the assumptions made in climate modelling be flawed? Seems to me this is the only area where it is even legitimate to question the human effect on the climate. Skeptics have been gleefully pointing to doom and gloom predictions that failed to materialize, but it also seems that some of the predictions have come to pass, I'm not sure if we will be able to stop it, but many of the measures we can take to try and curb it have other benefits as well. Even if global warming were a hoax, there are plenty of other harmful forms of pollution that come from our current energy mix and clean energy seems like a worthwhile endeavor to me. And if the sport of skiing could possibly be threatened, even more so.
Good points. Earth systems cycles are indeed complicated, but that doesn't mean giving up on trying to understand them. The history of science is full of disproven and modified theories as more and better data was gathered. But this isn't a fault of science, it's part of the scientific process. And I agree, there are many benefits to clean energy beyond climate change.
What I'm not clear on in those snow level charts is the impact of moisture content in the snow. Is it taken into account? Or is that already factored in as "snowpack" vs snowfall?
Two things the general public (here in the U.S.) doesn't think about: 1) The role of the oceans as a heat and CO2 sink, and 2) though temperature changes may not seem dramatic here in the U.S., they are more dramatic in other parts of the world. (Watch BBC World News or a European country's news and climate change is discussed without controversy).
Water has a high heat capacity. The earth's surface is 70% water, mainly ocean. CO2 dissolves in cold ocean water and in warmer ocean waters, is precipitated mainly as shells of sea organisms. This cycle can be traced by analyzing oxygen isotopes in the shells. Recently, this cycle has become disrupted by an increase in ocean temperatures, as shown by changes in ocean water chemistry that is, most notably, killing off coral reefs (a big CO2 sink). So this starts a positive feedback loop, in which the problem keeps getting worse,
2) The U.S.seems to be the only country in the world that views climate science as debatable. I think this is partly due to the general population's lack of respect for and understanding of the scientific process and failure to read world news. Having been fortunate enough to travel to different parts of the world, I've noted clear differences in attitude regarding those 2 factors.
(I am a chemistry teacher, and in the past few years, I've been shocked by the number of students who "believe" climate change is a hoax, while having no real scientific knowledge to back up their claims).
Pugski members who live overseas:What is your take?
Climate change is mostly discussed here in reference to the ski industry, but as
@Monique rightly points out, water supply is the crucial issue. Moreover, the huge migration of refugees from the Mideast is seen as partly due to climate change (drought). South Africa is seeing its worst drought in decades, causing a food crisis.
The big take-away is to pay attention to what's happening beyond our borders, and to respect those with expertise when forming policy.