Marking Earth Day . . . Or Not

There is much discussion about Earth Day, and how what I call traditional environmentalism misses the mark.  It's really past the point of saving whales and things like that.  From the looks of it, we've already got a developing mass extinction on our hands.

The funny thing is, a lot of people think all this is hypothetical: "oh, we can't ruin the economy to solve a problem that might not be real," or some such general failure to face what is going on.

One of the more interesting things is what's going on with the jet stream.

The basic version is, the Arctic is warming way faster than thought possible a few years ago, and that is changing the way the jet stream works.  No one knows for sure how that will develop, but it's already disrupting agriculture quite severely.  That has the potential to badly disrupt political stability in various places, and will screw up people's food supplies.  I'm sure storms and droughts and floods and other extreme weather effects don't affect the economy at all.

So here's an idea to "observe" Earth Day: do something to increase your own personal food security and health.  Grow a vegetable in a pot (it's a start).  Simplify your diet by cooking your own simple foods (much cheaper).  Get a good reference on nutrition - even "engineered" sports foods have work-arounds that actually are healthier and work better.

Be healthier on less money and gear up for simpler living that might be a make-or-break skill set.  And cause fewer emissions in the process.  Sounds like a win-win to me.

Miami Will Not Be There In 100 Years

The ice that will melt and submerge Miami is sitting in water that has gotten too warm for it to survive.

The great ice sheet on the western half of Antarctica sits mostly below sea level.

The vast majority of heating involved in global warming goes into the oceans.  It has been warming the oceans around Antarctica for decades.

That warm water has begun melting Antarctica.  The ice that sits below sea level is no longer stable.  The only physically possible way to stop it would be to cool the ocean.  There is no known way to do that.

So, in 40 or 50 or 60 years or something, we will lose Miami (and Venice, and the Portlands and . . .).

That is Miami with just over 3 ft (1 m) of sea level rise.  West Antarctica will cause about five times that.  Parts of East Antarctica will be lost too, as well as Greenland.

In the same amount of time since the creation of the United States of America, the coastal cities where so much founding history was made will be far under the waves.  Other nations have far more history that will be forever lost.

The first several feet will do the majority of the damage.  No city can withstand the level of lost infrastructure shown in the above map of Miami.  That will happen in decades to a century at the very extreme conservative edge, but it will happen.  And it won't stop there.  We've probably locked in something like 70 ft (about 25 m) of sea level rise.

The implication is that kids today will grow up and raise their own children in a world where coastal cities are being abandoned.

That is the heritage that has been made for them.

Check, Check, Check . . .

James Hansen is retiring from NASA.

He is one of the leading climate scientists in the world, and has been for decades.  He's been more right longer than anyone else.

In 1981 (!) he and his team did a study entitled, "Climate impact of increasing atmospheric carbon dioxide" in which some predictions were made about what we would face in the (then) future.  These have begun, far ahead of schedule, and are accelerating.  From the abstract:

Potential effects on climate in the 21st century include the creation of drought-prone regions in North America [check] and central Asia [check] as part of a shifting of climatic zones [check], erosion of the West Antarctic ice sheet [check] with a consequent worldwide rise in sea level [check], and opening of the fabled Northwest Passage [check].

Sea level is in fact rising because of melting ice sheets, about a third to a half of the 3.2 mm/yr happening now.  Ice sheet contribution is doubling about every 7 years, but it's pretty early in the process to see exactly how that is going to go.  It will be either fast or really fast: kids alive today will see the loss of cities like Miami either near the ends of their lives or in the middle.  We should have a better sense of timing in 5 or 10 years.

The short version of sea level rise is that the ocean has been taking in enormous amounts of heat, so ice sheets (like West Antarctica) that are grounded below sea level cannot survive.  In other words, something on the order of 70 ft of sea level rise now is unavoidable.

Protecting Our Way of Life

There are people who reject the very notion of climate change because they feel the whole situation threatens their way of life.

They see "environmentalism" as a religion that other people are trying to force on them.  They feel their values are being labeled as "bad" and their culture being targeted for elimination.  They see their goals and aspirations as being dismissed.

The fact is, no one wants the level of destruction that is headed our way, not even those who promote lies about it.

Coming to terms with what is happening is difficult and painful and profoundly disappointing.

It's as though we're on a luxurious cruise ship: the food is delicious, the music beautiful, the furnishings warm and comfortable.  Then the ship lists suddenly.  To the lifeboats: cold wind, choppy waves, not even enough space. The Titanic has hit an iceberg.

Climate change is like that.

We'll be leaving the lap of luxury whether we like it or not (I can't imagine anyone would).  There will be loss.  There will be sacrifices.  There will be a more comfortable existence left behind.  No one intends on voyaging in a lifeboat.

But if we're diligent and hardworking (and lucky), our way of life will survive.

"Way of life" invariably means different things to different people.  Driving a four wheel drive truck up and down a wilderness stream at full throttle for fun probably will go by the wayside.  But there are other ways to experience nature.

So it depends on what you care about.  If you care about being outside and having fun, that can still be done, but how it is accomplished might need to change.

In a warming world a lot of the luxuries we enjoy won't be there.  Having good quality of life is going to require some changes.  Some changes will be needed if we are going to avoid further damage.  Other changes will be needed to deal with damage that can no longer be avoided.

We have hit an iceberg.  We need to man the lifeboats.  It's not that anyone wants to, but it's what we have to do if we're going to be okay.

This Is Not Your Grandfather's Pollution

Well, in a sense it is.  CO2 increases from early in the 1900s still are floating around the atmosphere.  But the problem we have isn't anything like what people are used to thinking about . . .

David Roberts gave a talk last year about how climate change is simple.  His body language and tone of voice show that he gets it.  We are in really serious trouble.

He wrote a new piece about two reasons climate change is not like other environmental problems.

They boil down to this: it's permanent.

First he talks about the permanence of CO2 emissions.

To make this clear, let’s use the old bathtub analogy. The faucet is the source of the pollutant. The tub is the environment. And the drain represents the means by which the pollutant exits the environment. The key fact to remember: The damage to public health is determined by the total amount of pollutant in the tub.
Take a familiar air pollutant like particulate matter. We are spewing it into the air from tailpipes and smokestacks (the faucet). It leaves the air through simple gravity (the drain). Most of it falls to earth in days or weeks.
So when it comes to the particulate-matter bathtub, the drain is very large. We can reduce the total level of particulate matter in the tub any time we want; all we have to do is turn the faucet down, or off, and the tub will drain rapidly.
Carbon dioxide is not like that. Once it’s in the tub, it stays there for up to 100 years before it drains out. And the drain in the bathtub (so-called “sinks” that absorb carbon out of the air, like oceans and forests) is comparatively small relative to the enormous amounts coming out of the faucet. And by the way, we’re actively making the drain smaller by cutting down forests and carbon-loading the oceans.

This makes for a very different situation. Even if we cut our emissions by a third tomorrow, we would still be increasing the total amount in the bathtub:

The other issue  is that once things get heated up, they stay heated up for a long, long time.

But as this 2009 paper in Nature (among many others) makes clear, it doesn’t work that way:

This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. [my emphasis]

This is not the time cycle of particulate pollution — days or weeks — it is the time cycle of the Earth’s basic biophysical systems, which move much more slowly. A thousand years is not “forever,” but in terms of human agency it might as well be.

 These are two things most people haven't really internalized.  Things like acid rain can be cleaned up.  Even the ozone hole can be cleaned up.  We're doing something completely different.

Arctic Throwing Off Its Coldness

. . . and it is landing on us.

It used to be that the Arctic was always intensely cold and that cold was kept in place in the extreme north.  But now the Arctic is having fits of not-so-intensely-cold, and that is screwing up the cold-holding-in-place mechanisms of atmospheric circulation.  Some new research is looking at that:

The satellite record since 1979 shows downward trends in Arctic sea ice extent in all months . . . Previous studies have linked changes in winter atmospheric circulation, anomalously cold extremes and large snowfalls in mid-latitudes to rapid decline of Arctic sea ice in the preceding autumn. Using observational analyses, we show that the winter atmospheric circulation change and cold extremes are also associated with winter sea ice reduction through an apparently distinct mechanism from those related to autumn sea ice loss. . . .

So, there are multiple ways that atmospheric circulation is changing.  Atmospheric circulation is changing.  It's not hypothetical; it's being measured.

There are several root causes at work here.

One of the more fundamental is "albedo flip" which is a fancy term that says, when snow melts and things get darker, they heat up enough to stay that way.  There is no going back.

Another is that a warmer, melted Arctic Ocean has less of an ice lid to keep water from evaporating out into the sky.  Water vapor is a strong greenhouse gas, so amplifies what warming caused the melting in the first place.

These and a few other things are causing the Arctic to "flip" to a melted and much warmer state.  Having warmth where there used to be intense cold wreaks havoc with the physics of atmospheric circulation.

It's time to think about dealing with weather extremes, because there is a certain amount of "runaway" that has begun to happen and will continue until it has run its course.  How long that will be depends on whether other runaway processes will be tipped.  Odds are this will be the first of a long line of dominoes.

Plants that Migrate 450 Miles in 30 Years

They don't.

But growing zones in Canada and elsewhere have moved that far.

Winters are already significantly warmer and shorter than just 30 years ago. The temperature regimes and plant life of the south have marched more than 700 kilometres northward, new research shows. . . .

This is the stuff of mass extinctions.

If you believe in that kind of stuff.  Environmentalism is a religion, you know.  I'm not sure if it is the math or the physics or the chemistry or the geologic evidence that has led people astray.

Supposing The End

Methane is belching out of the Arctic.

The end of the world is an odd thing to think about.  It doesn't seem real, even in looking at the physics and the geology and the ground truth of what is happening and what might.

And, smart people can and do make mistakes.  Sometimes something cannot - must not - be allowed to be true, so it is explained away.  Sometimes the fallacy underpins some belief system, and even seriously listening to "the other side" is tantamount to blasphemy.  Conservatives do this.  Other times people make predictions that end up being lines in the sand from which they cannot bear to withdraw.

But regardless of human psychological malfunctions, there are hard, cold, facts that are not easy to accept as true.  One is the idea that Earth could warm enough that human life is essentially impossible on most or all of the planet.

One feared possible path to that end involves methane.  It is a much stronger greenhouse gas than CO2, 100 times stronger in the short term.  There is an awful lot of frozen methane in the Arctic.  If it thaws and is released as methane, we are in big trouble fast.  If it gets digested to CO2 by microbes on the way out, we're still in big trouble, but slower.

An end of the world scenario is being discussed, with no immediate technical rejection of it.

It is essentially a cascade of runaway events.  First the reflective (and cooling) features of the Arctic are lost.  They are now.  Then massive amounts of super-greenhouse gasses are released.  This too has started.  Then water is evaporated in very large quantities to further boost the greenhouse effect.  Earth's warming runs away and a Venus-type state results.  Mostly this depends on methane being released fast enough to do that.

I don't know if it is possible or not.  But I do know that what is happening now was thought next to impossible less than 10 years ago.

Volcanoes Damped Recent Warming

We've been putting ever more CO2 into the atmosphere, which should be causing ever faster warming.  But warming has not been as fast as expected (globally) since around the turn of the century.  What's going on?

We recently went through the deepest solar minimum in a long time, but solar cycles have too small an effect to explain it.  Turns out it's mostly been aerosols.

Earth can be cooled by a kind of atmospheric sunscreen: sulfur gasses make tiny droplets - aerosols - that are reflective and have a cooling effect.  In fact this idea is being advanced as an emergency cooling measure: aerosol-forming compounds can be sprayed by aircraft.

Aerosols don't stay in the air very long (months to a few years), so aerosol spraying would have to be kept up.  CO2, in contrast, stays in the air for thousands of years.  As soon as the aerosol rains out, wham!  Warming comes back.

You can see the effect of volcanic cooling (Mt. Pinatubo in 1991), and the recent slowdown of warming, in the most recent NASA data - note the dip to the right of the word "Global":

Direct measurements showed that there were aerosols coming from somewhere.  It was assumed, since there haven't been enough really big volcanic eruptions, that the aerosols must have been coming from dirty new coal plants in Asia.

It presents the same problem: when you clean up coal plant aerosols, the warming that was masked will come to bear.  That's more or less what happened when post-WWII emissions were cleaned up to fix acid rain and other problems.  Warming started in earnest in the mid-1970s.

But it turns out that a lot of smaller volcanoes can do it too.  Close study reveals that's what's been happening.

The implication is that we have a lot of warming that's been hidden.  Time will tell how volcanoes behave in the future.  What they do, and how long aerosol shielding lasts, will have a big effect on how much warming happens in the coming years.

Arctic Sea Ice is Peaking

Sea ice in the Arctic Ocean is about at its maximum for the year.

Sometime within the coming weeks it will begin its melt.  It is setting up to be another record breaking year.  You can't tell by that plot, but the ice is extremely thin.  It's also breaking up from wind, nearly 2 months ahead of last season.

The ice is melting from the bottom faster than from the sides.  It's a little like when I used to watch ponds melt in the fields around where I grew up.  The ice would retreat a little around the edges, it would get melted spots in the ice surface, and then it would all go away really quickly.

We are to the going-away-really-quickly part with Arctic sea ice.

Ice reflects almost all the light that hits it, but open water absorbs almost all light.  It warms as a result.  The same thing has been happening with land snow cover, actually faster.

So this melting and warming is feeding on itself.  Almost all of the sea ice that was there in 1980 is gone; last fall's volume was about one fifth of what was there in '80.

Most predictions used to be that Arctic sea ice would last until the turn of the next century.  Then it was mid-century.  Now most are saying 2020 or 2030.  But if you follow the volume plots, it looks more like 2 or 3 years from now.

We shall see.

Where No Man Has Gone Before

Atmospheric CO2 is pushing 400 ppm.  If you account for other man-made greenhouse gasses, we are closer to 500 ppm equivalent.

The last time the atmosphere had 400 ppm CO2 was millions of years ago.  That was before humans were even . . . however humans ended up here.

The plot above shows a recent reconstruction of global temperature since the end of the last ice age over 10,000 years ago.  The beginning of civilization is on that blue line.

Ice ages normally end fast and restart slowly.  The restart toward a new ice age is the cooling that started around 6000 years before present.  It was caused by slow orbital changes that drive the ice ages.

We reversed it.

Earth should still be cooling.  It stopped because we started dumping burned coal into the air, raising atmospheric CO2 from around 280 ppm to about 394 ppm now.  We're increasing CO2 at about 2 ppm per year, which is orders of magnitude faster than it happens naturally.

If we do nothing more the climate will stabilize at a level never before experienced by any human.  But we can't seem to stop.

If we don't stop, two things will happen.

First, natural feedbacks will take off, out of control.  Forests will burn, frozen carbon in the Arctic will thaw and be released, and lots of things like those.  Second, our emissions will add even more CO2.

The feared end state is a CO2 level of around 1000 ppm.  The last time that happened was tens of millions of years ago, when the planet was around 30 F hotter than now.

Earth has been there before, so no worries, right?

Well, making that change so fast is a little like driving around a corner.  Everything is fine at normal speed.  But at 120 mph, you have a problem.

That's what we're doing: going to a place mankind has never been, at a speed of approach that is insanely fast.

Going Rogue

Some days I feel like this woman:

Sea Ice Resources

Arctic sea ice is at record low levels now, with weeks remaining in the melt season.  Below are some sites where ice levels are tracked.

The best source of news and analysis probably is Neven's Arctic Sea Ice blog.

A page with gobs and gobs of graphs and maps is here.

The Cryosphere Today has good daily maps and a sea ice area plot.  Here is yesterday's map.

Sea ice extent is defined as where ice covers at least 15% of the sea surface.  daily values are available from the Japan Aerospace Exploration Agency (JAXA).

This is today's:

Enjoy.

Weather Extremes

For a very long time (decades) scientists have predicted that the distribution of weather we get would shift toward higher temperatures.

Well, that has been happening:

More information about that graph, and the science behind it, can be found here.

What the graph says is that heat events that used to be very rare now are quite common.  The extreme events that used to happen less than 1% of the time now are 10% and more.

There are important implications to dealing with this.

First, these events come in heat waves like the one that hit the US this spring, causing fruit trees to bloom early and then have buds killed by frost when the heat wave ended.  In other words, heat waves can come at the wrong time and screw up the way nature works.

Second, the severity of the heat waves causes problems.  Heat causes drying, and thus drought.  Dry soils don't supply water for evaporative cooling, which drives temperatures up even further.  Heat begets heat, as they say.  So you end up with very intense heat waves that kill by sheer temperature.  There was a "global warming type" drought, i.e., not just dry but also very hot, in the Southwest in the early 2000s which killed pinyon pines by heat, which was pretty much unheard of.  It was about an 800-year drought.

Well, an 800-year drought according to the climate we used to have.  There have been an awful lot of 100-year and 500-year and 1000-year events in the past several years.  That's what the graph above is all about - extremely rare events now are becoming common.

This is Probably Bad . . .

Tell me if this doesn't sound like something from a sci-fi horror movie:

About 5 years ago most scientists thought Arctic sea ice would melt almost completely by the end of this century.  That was so serious and scary NASA made videos showing how serious and scary the model results were.  Pretty much no one else cared.

About 3 years ago they said it looks more like 2030-2040 or so, within the lifetimes of people alive today.  A few scientists said it could be more like 2013 to 2016.  Big gulp, check and recheck the math, try real hard to have faith in the models that even today are not capturing the speed with which the Arctic is melting.

A year or so ago they realized the acceleration was seriously screwing with the weather.  The jet stream doesn't work like it used to.  It's slower now, wavier.  It stalls out, causing all manner of extremes as systems that used to pass on through sit there and build.

Now more and more scientists are saying the 2013-2016 guys are maybe right.  It's pretty obvious: if you look at the amount of ice actually in the Arctic Ocean, it's falling off a cliff.  From here:

That red dot is this year's minimum to date, as of late August.  We still have a few weeks of ice loss left.  But you can see already that the end of year-round sea ice is upon us.

No one knows exactly what that means, but chances are it will be pretty severe.

Fundamentally the way the Arctic screws up the rest of the Northern Hemisphere's weather is that it stores huge amounts of heat during the summer and releases it during the winter.  All that heat makes the atmosphere circulate differently.

So we can expect more extreme weather.  Possibly much more extreme weather.

Strategy Overview: Food

A look at the FAO Food Price Index shows that we have a problem:

Looking at that graph you can see that there are two things going on in recent years:

1. There is an overall trend of rising food prices.
2. On top of that trend is a pattern of instability.

These are the two basic features of the effects of resource depletion.  The resource (in this case food) becomes gradually more difficult to acquire, and the difficulty of acquisition can go through "shocks" or similar.  This doesn't just mean price, but instead encompasses more penetrating problems like basic availability.  For example, so-called "food deserts" are starting to develop where grocery stores have closed down and locals need to drive many miles to get their food.

Two strategies can be used to deal with this situation, not only for food, but for many other resources.


Guarding against price/availability shocks

The short description is hoarding.  Think "squirrel."

The basic concept is simple: if some food item will not be available for six or nine months, you build up a supply ahead of time.  This is not a new idea.  It used to be standard practice for people in rural areas to do this.  My mom used to put lots of food away every year so that we would have cheap and healthy food while fresh food from the garden was unavailable.  All of my friends' mothers did this.

These days most people use "just-in-time" food supply and buy food as they need it.  The problem comes when money is tight and then some essential component, like food, becomes expensive or otherwise hard to get.

The main issue is storage.  At first glance that seems to be just a matter of finding some extra room.  The real difficulty though is preserving the quality of food.  It might go bad.  It might lose its nutrient value.  It might be attacked by rodents or insects (grains often have insect eggs within them).

What it comes down to is re-discovering knowledge that used to be commonplace.  Canning, drying, dry storage techniques for grains.  There is a lot to know about these things.  It is prudent to learn about them ahead of time and work out the kinks in your own situation.


Dealing with long-term price/availability problems

You can hoard packets of tasty and nutritious instant oatmeal, but when they become completely unavailable or too expensive for resupply, you have a problem.

Getting around this requires systemic change and often a little creativity.  Substitution with something that is more reliably available becomes necessary.

For example you can buy quick oats by the 50-lb sack and add dried fruit and spices as you please (or not).  You can still cook it in the same microwave and use the same cup just like you did with your packets, but keeping yourself in oatmeal is now radically more robust and economical.

Going down this path generally involves some level of growing your own and changing the foods you acquire.  The bottom line is, you have to develop a food supply that is stable and secure.  That might mean having your own garden or it might mean having some arrangement such as a local farmer's market or shared garden space.

These two strategies, hoarding and finding alternatives, are applicable to a variety of similar problems.  You can ride a bicycle instead of drive for many activities.  You can use a Linux-based computer or open-source software instead of unnecessarily paying for proprietary software.

In concept these things are very simple.  In practice they are not easy.  It takes a lot of know-how that has been discarded by modern culture.  Getting up to speed with reliable technologies takes some effort and persistence.

Sixteen Degrees C

A paper out in Science suggests unfathomably severe warming of 16 C if Earth hits 1000 ppm atmospheric CO2.

We are presently at around 390 ppm, increasing at a rate of about 2 ppm per year. The increase is due to industrial CO2 output and other anthropogenic changes such as turning forest to fields. The actual output from human activity is more like 4 ppm, but around half of it is absorbed into the oceans. The industrial portion is growing at a few percent per year or so.

Thus, if we stay on our present emissions path, we will end up with an atmospheric concentration of around 1000 ppm by century's end.

Three main factors could change that outcome. In simple terms they are:

1. economic collapse or energy sector changes, which would suppress industrial emissions; 
2. slowing of the oceanic carbon sink, which would increase the fraction of emissions that stay in the atmosphere (warm water dissolves less gas); and
3. natural carbon reservoirs like permafrost, which already are emitting some gas (e.g., here), could pick up speed and dump their carbon stores into the atmosphere through bacterial action on stored organic material.

It appears that anything above 400 ppm or so, which is unavoidable at this point, will melt enough permafrost to cause an unstoppable, albeit slow, release of carbon sufficient to bring us to something like 1000 ppm.

In other words, it would appear that there is a very good chance that Earth will see 1000 ppm at some point in the next few hundred years regardless of what we do now.

Back to the Science paper.

The author reviews the paleoclimate record to see what happened the last time Earth had an atmospheric concentration of 1000 ppm. This was around 30 million years ago, but the date is poorly constrained (it could be 100 million years ago) because of uncertainties in ancient CO2 concentrations. He takes temperature estimates from a few places in the tropics and near the poles, makes some basic assumptions about the global temperature distribution, and adjusts for the fact that the Sun was a little bit dimmer then.

The global temperature is estimated to have been around 16 C warmer than now.

Without getting into nuts and bolts, this is very, very bad.

A while back there was a study done about the limits of human adaptation.  It focused on the fact that, when combinations of heat and humidity produce a wet bulb temperature of 35 C or more, the human body ceases to compensate.  In other words, that is a lethal condition for humans and other mammals.  This essentially does not happen now.

You start to get regional occurrences of this lethal, wet heat at global warming levels of around 7 C.  By 12 C half of the area inhabited by humans becomes subject to killing heat waves (see image below).  Add another 4 C to that and you have the world that could very well develop within a few centuries.

A separate consequence of warming is drying of soils.  The short version is, by the time you hit 4 C of warming you have a world where most of the breadbaskets turn to desert.

The above image shows what is expected with something like 560 ppm CO2 by mid century.  The scale is the Palmer Drought Severity Index.  During the Dust Bowl conditions were around -3 with brief excursions to -6 during the driest times.  This represents the complete destruction of an awful lot of agricultural land.

The only remotely comforting thing about the prospect of reaching 1000 ppm is that the full brunt of these climate changes would take longer to develop than my life will last.  Warming of 4 C is possible by mid century.  Seven C, and the beginning of lethal wet bulb temperatures, could happen around the end of the century.  The full 16 C (or more!) would take several hundred years to develop.

Videos: Atmospheric CO2, Silly Stuff

800,000 years of atmospheric CO2 from NOAA's Carbon Tracker Channel on YouTube.

That can be a little depressing when you think about it, so . . .



This is just classic:



The Australia reference is from the novel and later movie, On the Beach, about fallout from a nuclear war slowly destroying the world.

2010 Ties as Warmest Year, Brings Extreme Weather

NASA and NOAA both are reporting that 2010 has tied with 2005 as the warmest year on record.  A plot of the NASA data:

It was also the wettest year on record.

The link between warmer and wetter is pretty straightforward: warmer air holds more water (about 7% per degree C of warming).  A warmer atmosphere also circulates more vigorously.  You might think of the atmosphere as a sponge which has gotten larger and gets wrung out more thoroughly.

Ironically, the same things that cause the atmosphere to become more heavily loaded with water (to oversimplify: enhanced evaporation) also can cause soils and plants to dry out much more quickly.

Climate Progress has interviewed climate scientist Kevin Trenberth, who had this to say:

I find it systematically tends to get underplayed and it often gets underplayed by my fellow scientists. Because one of the opening statements, which I’m sure you’ve probably heard is “Well you can’t attribute a single event to climate change.” But there is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago. It’s about a 4% extra amount, it invigorates the storms, it provides plenty of moisture for these storms and it’s unfortunate that the public is not associating these with the fact that this is one manifestation of climate change. And the prospects are that these kinds of things will only get bigger and worse in the future.

Trenberth has written a paper, Changes in precipitation with climate change (PDF), which gets into the gory details.

Perhaps more worrying is this Climate Progress quote from meteorologist Dr. Jeff Masters, discussing the huge increase in extreme weather events in 2010: 

In my thirty years as a meteorologist, I’ve never seen global weather patterns as strange as those we had in 2010. The stunning extremes we witnessed gives me concern that our climate is showing the early signs of instability. Natural variability probably did play a significant role in the wild weather of 2010, and 2011 will likely not be nearly as extreme. However, I suspect that crazy weather years like 2010 will become the norm a decade from now, as the climate continues to adjust to the steady build-up of heat-trapping gases we are pumping into the air. Forty years from now, the crazy weather of 2010 will seem pretty tame. We’ve bequeathed to our children a future with a radically changed climate that will regularly bring unprecedented weather events–many of them extremely destructive–to every corner of the globe. This year’s wild ride was just the beginning.

Emphasis mine.  (More on that later.)

The increase in rainfall presents a huge problem for infrastructure, not only because existing infrastructure is unable to handle the associated increases in runoff, but also because engineers have no good way to decide what to design for.

For example, a normal design criterion is to make the design (a road or drain system or bridge or whatever) able to withstand a "100-year" storm, i.e., a storm which has a 1 in 100 chance of happening in any one year.  But now many areas are having 100-year storms about every 5 years.

What to do?

I saw one very sophisticated and elaborate study that went to great efforts to get data for the last 150 years.  They did a fabulous analysis on that data and published beautiful color maps of 100-year (and 5-year, 10-year, etc.) storms for use in engineering design.

That's nice, but our climate started on its present path in the mid-1970s.  Anything before that reflects a climate which no longer exists.

There is a saying in shooting: "You cannot miss hard enough."

Loss of Greenland Ice Sheet Possibly Unavoidable

Modeling results from the Danish Meteorological Institute suggest Greenland's ice sheet might be past the point of no return already.  Politiken.dk reports:

The result of an international scientific paper, based on data and models from the Danish Meteorological Institute, is suggesting that an eventual meltdown of Greenland’s ice-cap is almost unavoidable. . . .

After 2040, on a time scale of 1,000 years ahead, it will not be possible for the giant Greenland ice-cap to be re-created and return to current levels.

“Over the next 30 years the amount of snowfall will not compensate for melting,” Hesselbjerg Christensen tells pol.dk adding: “Based on our model, I would almost say that the point of no return has already been passed. Our result shows in principle that permanent meltdown is unavoidable.”. . .

Greenland has some interesting mechanisms of ice loss, some of which were unknown just a few years ago.

There is the obvious surface melting, which is how people would normally think of an ice sheet being lost: warm air, rain, etc. melts the ice from the surface.

The resulting melt water causes some other interesting effects.  One is a lubricating effect.  When melt water finds a crack in the ice, it wedges the ice open and can create a conduit that brings the water deep into the ice sheet, all the way to bedrock.  This water both lubricates the flow of ice and warms the ice, softening it.

There has been some speculation that large masses of ice might get warmed and soften sufficiently that it won't be able to support its own weight.  That would create episodes of "iceslides" if you will: sudden structural failure of city-sized areas thousands of feet thick.  It would be quite something to see.

Another mechanism of ice loss from Greenland is warm ocean water melting glaciers at their outlets from below.  Some glaciers in Greenland are grounded below sea level for quite a distance inland.

In the future it is expected that, as the height of the ice sheet is reduced by ice loss, the warmer air at lower altitudes will cause even faster melting.  So, once the ice sheet loses a certain amount of altitude it will be impossible to stop further melting without significant cooling of the climate.

The complete loss of Greenland would raise sea level by an average of around 7 m.  This process had been expected to take a thousand years or so, but the discovery of previously unknown mechanisms outlined above shortens the timeline significantly.

It is hard to say how fast this could go.  Present warming is proceeding about 10x faster than at any time known from the geologic record.  A couple of hundred years perhaps?

You would have to assume the loss of Greenland would be accompanied by the simultaneous loss of West Antarctica (~5 m worth of rise), which is even more unstable, as well as some unknown contribution from East Antarctica.

If you figure losing half of Greenland's ice mass in 200 years with an equal contribution from West Antarctica, that is 3.5 m (Greenland) plus 2.5 m (W. Antarctica) over 200 years or 3 m per century without even considering East Antarctica.

Previous deglaciations have produced sea level rises of 2.5 m per century and perhaps as much as 5 m per century, with a much slower warming.

Regardless, it is very difficult to see much more than about 1 m by mid-century.