If you have to hear bad news, there's no better way to be told than from the mouth of Gwynne Dyer. If anybody could announce the apocalypse with the appropriate mix of concern and curiosity, I'd vote for the dire Dr. Dyer, journalist and historian.

In fact, this is almost what he does with his silky baritone and customary irony on a three-part series on Ideas called Climate Wars. (He's also written a book with that title.)

Over the years, Dyer has been a regular fixture on the CBC. Born in Newfoundland, though you can't tell by his accent, he's a foreign affairs and military analyst based in London, England.

Hindus bathe in the Ganges during a holy day in January 2009. Will it be the source of a climate war if its headwaters dry up? (Rajesh Kumar Singh/Associated Press)

No doubt you've seen him on TV with his trademark goatee and weathered green, leather jacket. (I understand he's on his second one.) He's served in three navies, the U.S., British and Canadian. The jacket is his civilian uniform.

Now, if you're like many CBC listeners, you've probably heard your fair share of climate-change stories. Global warming has been everybody's favourite subject for a while now though lately it's been overtaken by the melting economy.

But Gwynne Dyer, with his mildly gleeful tone and curt, weathered irony, is the perfect person to tell us how we're heading for a real global disaster. His tone is avuncular so the message goes down smoothly.

'Positive feedback'

What's scary in this scenario isn't just the fact that the icecaps will melt, or the temperature will rise, or that some places will be soaked while others are turned into deserts. The really scary thing has a bland, scientific name: "positive feedback."

Positive feedback is, in effect, nature's tipping point. That's when one or several small events will trigger a cascade of bigger events, each more disastrous.

Right now, we think we're in at least partial control. We think we may be able to prevent global warming by curtailing greenhouse gases. But once positive feedback takes over, we become passengers on Mother Nature's roller coaster.

Dyer himself tells us that he really only started worrying about climate change when the Pentagon and other military planners began to worry.

During the George W. Bush administration, which never took global warming seriously, the generals had to hide their growing obsession with climate. So they began to farm out their work to institutes and then translated the findings into what they love to do: create war games.

Here's an example: by 2040, the glaciers at the headwaters of the Ganges, on the Indian subcontinent, will melt. There will be floods, then drought. Millions of people will be endangered. India and Pakistan share these waters. Both have nuclear weapons. A nuclear war may be triggered over who controls the remaining water.

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That's just one scenario. Another would see half of China turn into desert, sparking a war with Russia over a now temperate, grain-producing Siberia.

Then there is the prospect that Bangladesh will sink like the fabled Atlantis, drowning millions.

If nature takes a different twist, the European Union could break up. Northern Europe will wall itself off from super-heated Italy and the Mediterranean. Italy and Spain will demand food, threatening the north with sophisticated weapons.

Meanwhile, boatloads of Africans will pile into southern Europe, as they are doing now, only the trickle will become a human flood.

On this side of the Atlantic, Dyer thinks America will build a bristling wall between itself and Mexico. Equipped by electronic sensors and "shoot anything that moves" machine guns, Mexicans fleeing their starving country would be gunned down on the Texas border. U.S. Hispanics will rise up in anger and civil strife will break out in the larger centres.

Should that happen, it is not a big step to seeing an imperiled America making new demands on a once friendly Canada. Do you think we can stand up to a frightened superpower?

A debt to be paid

Aren't war games fun? You can become almost giddy hearing about them from the faintly cheery Dyer.

When will all this happen? That's the problem with scenario-mongering and trying to outguess a clever Mother Nature. Ten years? Twenty? According to Dyer, the smart money is on 2040.

If you were born in 1980, you'd be 60 and could well have grandchildren. What a legacy to leave them!

If you think we're borrowing now to fend off financial calamity, which your kids will have to pay for with their increased taxes, imagine their reaction when Mother Nature starts demanding eco payback.

Meet Father Greed

For this to happen, all it takes is a rise in global temperatures of a little more than two degrees Celsius, which is quite within the realm of possibilities. But really, who knows what number will set off the global apocalypse?

At the tipping point — the positive feedback marker — the sea ice will melt and wildfires will sweep the Amazon rainforest as well as Canada's boreal forest, already weakened by the northward lurching pine beetle. The Arctic permafrost will also melt, in the process releasing methane, a much more potent greenhouse gas than carbon dioxide.

The fact my RRSP tanked in 2008 seems like a benign news story now.

But these two events are actually linked. Overconsumption and a wasteful, fossil fuel-driven economy have created the conditions for this mess.

In the words of the New York Times columnist Thomas Friedman, this is what happens when Mother Nature meets Father Greed. Journalists can be mighty clever when opining about disaster.

This is good news?

But back to Dyer. A man who speaks this convincingly must leave us with some good news, right?

One area Dyer explores is "geo-engineering," technical fixes, like putting sulfur into the atmosphere to block sunlight or blanketing the sky with sun shields to reflect the sun's heat away from Earth.

These are measures that are highly controversial. But Dyer doesn't believe that today's policy makers will meet their own deadlines for fossil fuel reduction. And even if we do, we may trip over nature's tipping point, anyway.

So you come away after listening to Dyer thinking that he believes we will eventually have to try for some pretty large-scale techno fixes.

And it is in groping toward these large-scale fixes that hope may lie. Or, as Dyer sees it, that nations will come to see climate catastrophe as if it were an outside invader, then band together to fix the planet.

That's the sci-fi scenario and it's oddly comforting. A new empowered planet to rewrite the rules on how nations live with each other.

There is a wild card in this, of course, which Dyer is only too happy to point out: a planet under stress will create hordes of disturbed individuals, some of whom will have the technological wherewithal to create a round of terrorism that dwarfs anything we've seen.

"We didn't want to end on an up note!" joshes Dyer, at the end of the three-hour series. Dyer may be the only person I know who can get away with laughing at the apocalypse.