It really annoys me when people treat climate change purely as an environmental issue.

I care about the environment, probably more than most people. I pick up litter so birds won’t eat it and get sick. I’m maintaining three composting systems at the moment. When I have my own house one day, I’m going to tear up the sod and let prairie grasses take over the lawn so it becomes a habitat conducive to frogs and sparrows.

But I hold climate change in an entirely different category. It hardly even overlaps with the “environment” section of my brain.

Climate change certainly will severely impact ecosystems and the environment. Wildlife will be forced to adapt, shift its range, or face extinction. Droughts will lead to lower water levels in some areas, which increases the concentration of pollutants. Habitat loss, the other major threat for species, will be aggravated in many areas: forests, coral reefs, year-round ice, and lakes – to name a few – face stress from changes in temperature and precipitation.

But it doesn’t end there. Climate change is way too complex and far-reaching to be labelled as “just another environmental issue”. Yes, it is an environmental issue. But that’s the least of it.

Consider agriculture. A recent study in Science claims that average temperatures in the tropics and subtropics – areas which are home to more than 3 billion people, the majority of whom depend on community agriculture for sustenance and income –  are highly likely (>90%) to exceed even the warmest temperatures on record by the end of this century. “Experimental and crop-based models for major grains in these regions show direct yield losses in the range of 2.5 to 16% for every 1°C increase in seasonal temperature,” the report states, and “despite the general perception that agriculture in temperate latitudes will benefit from increased seasonal heat and supply food to deficit areas, even mid-latitude crops will likely suffer at very high temperatures in the absence of adaptation.”

An even more fundamental requirement for human survival is drinking water. More than one-sixth of people worldwide depend on glacial/snowpack meltwater to drink (IPCC AR4 WG2, 3.4.3), a source which could become threatened in the near future, as “many small glaciers, [especially in the Andes], will disappear within the next few decades, adversely affecting people and ecosystems.”

One of the scariest impacts is sea level rise. Nearly every major city in the world is coastal, and could be wiped out in the centuries to come. We’re only expecting an increase of 0.6 m by 2100, but there’s enough ice in the world to increase the sea level by 80 m, should sufficient warming come to pass. This would take at least a few hundred years, but consider how long some of those coastal cities, such as Amsterdam and Shanghai, have been standing, and how many years of cultural significance they contain. Imagine that we only have a few centuries left before we have to move everything in them – or lose them altogether.

It gets even scarier when you start looking at climate change from a national security perspective, at its potential for political conflict and resource wars. Scientists give the best estimate; but military officials prepare for the worst possible scenario. Unfortunately, most of these documents are classified – I can’t find anything unclassified that would qualify as an acceptable source under our comment policy. However, the Center for Strategic and International Studies (a bipartisan foreign policy think tank) recently published a fairly terrifying report on this topic. I’m also reading a book called Climate Wars, by Canadian journalist Gwynne Dyer, which contains cheery scenarios such as the breakup of the European Union (due to drought in southern Europe, leading to conflict with the north for food supplies) and a “Colder War” over Arctic sovereignty.

It’s not just about polar bears. It’s about the life, security, and prosperity of our civilization. It seems radically unfair to classify climate change as one of many environmental problems – somehow implying that it is just an environmental problem, no worse than commercial pesticides or eutrophication. We can’t fix this with a single law. We need more than a change in what kinds of products we buy. This is one of the worst problems, if not the worst problem, of our time purely because its impacts are so far-reaching and it is so hard to fix.

And that’s why it takes up so much more space in my mind.