The United Nations also states that increasing levels of various greenhouse gasses are primarily what is causing the climate to change:
"By absorbing infrared radiation, these gases control the way natural energy flows
through the climate system. In response to humanity’s emissions, the climate has
started to adjust to a “thicker blanket” of greenhouse gases in order to maintain
the balance between energy arriving from the sun and energy escaping back into
space. Observations show that global temperatures have risen by about 0.6 °C
over the 20th century. There is new and stronger evidence that most of the observed
warming over the last 50 years is attributable to human activities."
The largest contributor of greenhouse gas emissions according to the National Research Council is the burning of fossil fuels, which produces large amounts of CO2. As far as I can tell, human beings are the only creatures that burn fossil fuels and (in line with the above quote) very likely bear most of the blame with regards to increases in global temperature as a result of greenhouse gas emissions over the last 50 years. The National Research Council estimates that the concentration of CO2 in the atmosphere is increasing at a rate of about 2 parts per million per year. This trend seems likely to continue in the future as it depends largely on population change and economic development, both of which are, in general, on the rise. This will very likely cause further increases in global temperature, with current climate models predicting an increase of anywhere from 1.4 to 5.8 degrees C over the next century.
So what does this mean to us? So what if the temperature increases? I mean, sure, it will get a little hotter which sucks, but overall this isn't quite as horrible as people are making it out to be. Well, it turns out that's bullshit. Agricultural stress is one way in which the changing climate could impact us as humans. The United Nations states:
"Degrading soils and water resources will place enormous strains on achieving food
security for growing populations. These conditions may be worsened by climate
change. While a global warming of less than 2.5°C could have no significant effect
on overall food production, a warming of more than 2.5°C could reduce global food
supplies and contribute to higher food prices."
With some regions being more affected than others:
Added heat stress, shifting monsoons, and drier soils may reduce yields by as
much as a third in the tropics and subtropics, where crops are already near their
maximum heat tolerance. Mid-continental areas such as the US grain belt, vast
sections of mid-latitude Asia, sub-Saharan Africa and parts of Australia are all
expected to experience drier and hotter conditions. Meanwhile, longer growing
seasons and increased rains may boost yields in many temperate regions; records
show that the season has already lengthened in the UK, Scandinavia, Europe and
North America."
Another way in which the changing climate can affect us is through changes in sea levels. The United Nations points out that there has been an average worldwide rise in sea levels of about 10 to 20 centimeters over the last century and rising sea levels are expected to continue due to the changing climate. This produces a particularly haunting conundrum for those of us living in coastal regions such as some parts of Southern California and an even more serious one for those living in coastal regions of less developed areas. The United Nations states that small islands and coastal regions will likely be the most affected by the rising sea levels, with a large parts of the world already noticing these changes:
"Coasts have been modified and intensively developed in recent decades and
thus made even more vulnerable to higher sea levels. Developing countries with
their weaker economies and institutions face the gravest risks, but the low-lying coastal
zones of developed countries could also be seriously affected. Already over the past 100
years, 70% of sandy shorelines have been retreating."
These changes in sea levels will very likely also have negative economic impacts due to the fact that a good portion of our food is either produced or processed in coastal areas.
This obviously is not a happy topic. A lot of messed up stuff is either happening or likely going to happen in the near future if we don't change the way we are doing things right now. So why haven't we addressed this problem with the level of seriousness that it obviously needs? The answer is likely to be somewhere between laziness and politics. The laziness part seems pretty self-explanatory. Politics on the other hand, although probably all of us are familiar with the political push-back, is a little bit baffling if you really think about it. So why is this a political issue, and why do so many still deny the scientific communities' claims about our role in climate change even in the face of some pretty rigid evidence in favor of those claims?
The Heartland Institute is one of the leading organizations in the climate change denial world, and they have stated openly that they "focus(es) on economics, not science". One of the institutes major concerns is that they don't want increased taxes and regulation to deal with climate change unless it is absolutely necessary. They claim that 60% of the general population (most of whom are not scientists) does not believe that climate change or "global warming" is a crisis. Despite the fact that general consensus does not automatically equal truth, they seem to be quite proud of this finding. They have even gone so far as to post it on their website. The heartland institute makes references to the fact that many scientists "cast doubt" about the "so-called consensus on global warming". This quite blatantly ignores the fact that in order for a scientist to function properly in his/her job, he/she must always maintain a somewhat agnostic viewpoint with respect to what he/she is studying and acknowledge the possibility that he/she could be wrong. In other words, he/she needs to maintain a certain degree of doubt.
So the main reason why The Heartland Institute and others are still skeptical even in the face of hard evidence seems to be that they are concerned about how it will affect the economy. This seems noble enough, and as much as the economy may be hindered somewhat by increased regulations and taxes, the UN has already made it very clear that some dramatic negative economic changes are likely to occur of we don't act to change things. Despite all of this, it isn't hard to understand why some people still hold this point of view. Science is really freaking complicated and most people haven't so much as reached apprentice levels of understanding with respect to most scientific matters let alone master them. It seems quite natural that we as humans would be skeptical of things that we don't fully understand.
The conclusion though, is pretty... well... conclusive. Things need to change. I think there is a good chance that if we don't act now to curtail the climate change crisis, then by the time 2060 rolls around, we will probably be in pretty bad shape. I imagine that temperatures will reach levels hot enough to cause serious heat related illness far more often than now in areas where hot seasons are already excruciating. Not to mention, our economic condition will likely worsen due to agricultural stresses as well as the effects of rising sea levels on coastal and island regions. Overall, the world will likely be a far different place fifty years from now whether we attempt to fix our problem or not. However, if we do try to fix the problem, the chances seem much higher that the difference in the world will be for the better.
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