Few these days would question that Earth's surface is getting hotter. Helping to confirm this deduction is the fact that each of the last three years has seen a new record high in average global temperatures. A parent with a child born in late 2013 was wondering, "If this keeps up, how hot will it be when my son reaches 21?" The question, though, is whether or not human activity has played a significant part in the rise.

Is manmade global climate change a hoax or a reality already affecting weather and the biosphere and likely to continue to do so for the next 100 years at least? Others can lay out the debate better than I. The interested reader might find in my primary sources places to pursue further research. Suffice to say climate scientists have presented an impressive array of data in support of their conclusions that human involvement in the advancing mercury readings is a reality. Nonetheless, a large number of people remain skeptical. They have interesting arguments on their side as well.

I am not a climate expert, but am persuaded that if those who are have the right answer, then we would be as foolish to ignore their warnings as those who for decades contended that their smoking habits were not bad for health, despite mounting evidence to the contrary.

I am reminded of the saying by philosopher and mathematician, Blaise Pascal, that, to paraphrase, there is no harm in believing in God and no special benefit from being an atheist, but if the latter lives accordingly and is wrong, it could be very unpleasant indeed. Ergo, we may as well at least act as if there is a God. He said it better than I, and of course in French, but you get the idea.

Steven Hawking says the world will be uninhabitable within a hundred years directly as a result of global warming. He is so sure of it he says a few of us must colonize another world in order to avoid our species' extinction. If so, we might as well begin now to celebrate the late, great Homo sapiens, for the odds against our successfully colonizing another planet in that amount of time and being able to survive there independent of Earth are staggering.

If I get to a Y in the road in an unfamiliar area and a local Good Ol' Boy there tells me to take the right way because the other is shorter but leads around a sharp bend to a sudden drop-off, I'm going to certainly be cautious as I proceed but more inclined to veer right. The Good Ol' Boy might be wrong, but what if he is right?

That said, I respect those who look at the matter another way. I do not think it best to sweep the matter under the carpet because there are alternative opinions. Some of the greatest start-up companies, like Facebook and Google once were, have taught a valuable lesson, that we need to not squelch but address our differences. Only then can we find answers that take into account all perspectives and so arrive at truly win/win solutions, more likely to prove lasting.

If the skeptics are correct, we and the rest of the people on the planet can continue with business as usual, adding as much carbon dioxide (CO2) to the air as we wish, and there will be no significant or long-term cost in doing so.

Per NASA, however, with current production of the CO2 that is going into the atmosphere, temperatures will go up 2.5 to 10 degrees F (equals 1.4 to 5.6 degrees C) over the next century. Related to this, there will be more and stronger storms, droughts and floods will increase in frequency and intensity, sea levels will rise significantly, the poles will become ice free, glaciers will melt, the global system of sea currents will be affected, and within the next few decades each year's seasonal warm months will be extended by about 4-5 weeks (at the expense of the cool months).

Here is a degree by degree forecast of how the increasing temperatures would affect things:

1. With one extra degree C of global warming (1.8 degrees of average global increase F), the US Midwest will suffer severe droughts and dust storms, followed by desertification, the seas will rise enough to threaten many coastal areas, storms will be stronger and more frequent, there will be more fires, allergens will increase, and diseases will be more widespread. Crops that could be grown in many areas will no longer be feasible in those locales. Wheat, for instance, might not be able to be successfully grown in prior grain belt areas, but bananas might if there is sufficient rainfall. Fresh water would become less plentiful, though, probably threatening many millions of the Earth's human population. Low-lying atoll countries will be submerged. Arctic and permafrost regions will cease to be stable or supportive of wildlife, will reflect back into space much less solar energy, and will begin to release into the atmosphere the extremely powerful greenhouse gas, methane, accelerating global warming. With atmospheric CO2 at current levels, there is now likely nothing we can do to prevent these changes short of global thermonuclear war (which of course would temporarily put enough matierial aloft to blot out much sunlight for a couple years or more, i.e. nuclear winter).

2. With two degrees of global warming (3.6 degrees of average global increase F), anticipated by 2050, many cities will be experiencing lethal levels of heat stress. Hundreds of thousands if not millions of us would be in danger. Agriculture generally would be far less productive. The balance of polar ice shelves would melt. Sea levels would rise by 25-30 feet or more. Vast areas would be destroyed by fires. Tens of millions of refugees would be seeking haven in cooler climates, disregarding borders in their desperation to survive. Regional warfare would increase. Many sea creatures would go extinct. Miami and New York would disappear. Ecosystems will unravel. Failed states will multiply. Millions will have trouble surviving. If people reduce carbon dioxide emissions in a major way in the next few years, the worst of these developments can probably be avoided.

3. At three degrees of global warming (5.4 degrees of average global increase F), the Amazon River system will cease to be viable. More plants would be dying and releasing additional carbon dioxide into the atmosphere than are growing and absorbing it. Much of the sea would no longer be able to sustain life. The ocean's system of global currents, such as the Gulf Stream, would be affected and in some cases cease altogether. Air-conditioning will be mandatory to support human life in most areas. Vast regions will no longer have viable agriculture. Billions of people will be at risk.

If global heating has increased to this level, there may be irreversible and runaway effects, such as the deep thawing of permafrost regions, releasing huge amounts of methane and assuring still further roasting within the decades thereafter. As that heat trapping progesses, clouds of poisonous hydrogen sulfide could be released from the seabeds. Hydrogen sulfide is thought to have been a mass killer in the end-Permian event, when 95% of all species on Earth became extinct. As Stephen Hawking predicts, in such a world we would have trouble surviving as well.

If even the first two levels of Hell portrayed above come about, it would be a stingy gift to bequeath to our nieces and nephews, kids, grandchildren, and great grandchildren. Should we as a species, for the short-term convenience of an unrestricted use of fossil fuels, take a chance that we are wrong about whether or not our contribution to global warming is real?

Primary sources:

A Degree by Degree Explanation of What Will Happen When the Earth Warms in globalwarming.berrens.nl; July 20, 2017

Earth Could Hit 1.5 Degrees of Warming in Just 9 Years, Scientists Say Ian Johnston in independent.co.uk; May 9, 2017;

Is Human Activity Primarily Responsible for Global Climate Change? in ProCon.org; June 19, 2017;

When Will Climate Change Make the Earth Too Hot for Humans? David Wallace-Wells in nymag.com; July 9, 2017;

Why a Half-Degree Temperature Rise Is a Big Deal Bob Silberg in climate.nasa.gov; June 29, 2016.