Climate Change is turning out to be a lot more complicated than just plain old Global Warming. It's not just about the weather; there are biological, chemical, and geophysical manifestations all linked together. Which, among other things, means we have to pay attention to changes that might not be obvious at first glance.
Here's one that could be a biggie: the Arctic Ocean is becoming more acidic. Cold water can absorb more CO2 than warmer water, and the decreasing amount of polar ice exposes more water to CO2 in the atmosphere.
Scientists estimate that the average acidity of surface ocean waters worldwide is now about 30% higher than before the Industrial Revolution.
The researchers say there is likely to be major change to the Arctic marine ecosystem as a result. Some key prey species like sea butterflies may be harmed. Other species may thrive. Adult fish look likely to be fairly resilient but the development of fish eggs might be harmed. It is too soon to tell.
Organisms that live in water are very sensitive to water chemistry; the science report describing it is summarized in 10 key findings here. (Big PDF file) The Arctic Monitoring and Assessment Programme (AMAP) homepage is here; lots of resources.
It's not just the Arctic Ocean at risk of course. Increasing acidity is having effect around the world. But beyond that, one of the consequences of acidification is that the other things dissolved in seawater will change. Acid rain in the Adirondacks suggests one possible problem. Inorganic mercury compounds become more easily transformed into methyl mercury, which is more readily taken up into the food chain, leading to bioconcentration and bioaccumulation. This may be behind the problem driving down the arctic fox population. Those fox populations deriving most of their diet from the ocean are suffering from mercury poisoning. (Original paper here.) It's suggested that rising mercury levels in the oceans are linked to human pollution from industrial activities. Acidification may well be making a bad problem worse. But wait - there's more. NASA has found changing sea ice levels are also affecting mercury deposition and ozone depletion.
Even something as simple as predicting the rise of sea level as the Greenland and Antarctic ice caps melt turns out to be a lot harder. Paradoxically, sea level may actually drop in some areas as the ice melts. New Scientist has a report (free subscription required) which explains gravity is a factor.
If you think this sounds unlikely then you are in good company, as even oceanographers have struggled to accept the idea. Yet the physics behind it is quite simple and the basic principle was recognised as far back as the 19th century. The first person to do so was Robert Woodward, a physicist who worked for the US Geological Survey at the time when it was becoming clear that much of North America had been covered by ice not that long ago.In other words, just calculating the volume of water released as the ice melts and distributing it around the world to figure out how much the seas will rise won't work. The uneven nature of the earth's gravitational field means that water on the move will tend to pile up where the local gravitational attraction is higher - and the mass of the water piling up will increase the gravitational attraction even more.
Woodward was asked by his colleagues to help explain a puzzling finding: when the ice was present, the shoreline of one lake appeared to have been much higher on one side than the other. He realised that any large mass on Earth's surface, from a continent to an ice sheet, exerts a significant gravitational pull on any water surrounding it, piling the liquid against its flanks. In the case of an ice sheet, these watery foothills will subside if the ice melts. In 1888, Woodward published a paper describing ways to calculate the resulting changes in sea level.
Meanwhile, places where the ice used to be will see changes as well. Sea level around Greenland may actually end up 100 meters lower. That will in part be due to the lower gravitational pull from the loss of the mass of the melted ice caps, but also due to rebound by the earth's crust. Relieved of the weight of the ice, Greenland will start slowly rising.
And, to make it even more interesting, the redistribution of the the mass of the melted ice caps may affect the rotation of the earth, which normally causes a bulge in the oceans. Just where and how high it gets may shift. Again from New Scientist:
Removing an ice sheet is like moving a weight on the rim of a wheel: it alters the planet's balance. If Greenland melts, for example, that will shift our axis of rotation about half a kilometre towards the ex-icesheet. Our equatorial bulge in turn will tilt slightly. This adds extra bumps to the sea level fingerprint, moving the surface up or down by as much as half a metre in places (see diagram).Recent studies suggest the Greenland ice sheet is going to melt completely. We've passed the critical point. The next question is going to be what happens to the ice sheets of Antarctica. The changes will be even bigger.
Mitrovica's team showed in 2001 that by allowing for all these effects, they could explain the geographic variability in tide gauge trends. "That was the 'oh boy!' moment for us," he says. More people began to take notice, although it is only in the past few years that sea-level fingerprints have finally entered oceanography's mainstream.
Outside the field, the notion of shifting seascapes still comes as a surprise, says Mitrovica. "I still give many talks where people are shocked that sea level falls near a melting ice sheet." And his "near" is actually quite far. The long reach of gravity means sea level will fall within about 2000 kilometres of the ice.
Bottom Line: We're essentially running an uncontrolled experiment on our planet here that's going to take us to some pretty strange places. We're talking about myriad effects, some seemingly minor, others on a global scale, that are linked together in ways we're just starting to figure out. The time scale includes things that will unfold in our lifetimes, and processes that will run for centuries. There's no "Off" switch - we can't just stop now and expect everything to go back to where it was. The best we can do is start taking steps to limit the damage we've already incurred, and stop digging the hole deeper.
This is a really REALLY bad time to be cutting back on basic science and research. Space for one ought to be getting a lot more money; we really need as many 'eyes' on the planet as we can get at this point. (Like these, or this.)
We also need to do a much better job promoting and protecting science. There's an alarmingly large segment of the U.S. that believes there's no need to do anything because... Jesus! We have elected representatives who want to make sure science doesn't tell them anything they don't want to know. There's a saying - stupidity is a capital crime. We may be looking at a murder-suicide if these people prevail. And don't anyone dare claim market forces will save us. Greed is NOT good.
One more thing. It's worth noting that many of the scientists who have accepted the idea of human-caused climate change have made a number of errors in their work. Their predictions on how bad things are getting and how quickly... have often under-estimated just how bad it actually is.
UPDATE: In a country with a lot at stake when it comes to the Arctic, the suppression of science is Orwellian.
Help Us Spread the Word About Climate Change
For those of you on Facebook and Twitter: Please help to spread the word by hitting the FB and Tweet links at the top of this diary and if you have time, join the discussion with comments. Share such postings with friends, family, co-workers, and acquaintances.
Thanks, as all of this helps build the Climate Change movement as well as introducing critically important ideas about renewable sources of energy.
Please use hashtags #climate, #eco, and #climatechange to tweet all diaries about the environment.
After a hiatus of over 1 1/2 years, Meteor Blades has revived his excellent series. As MB explained, this weekly diary is a "round-up with excerpts and links... of the hard work so many Kossacks put into bringing matters of environmental concern to the community... I'll be starting out with some commentary of my own on an issue related to the environment, a word I take in its broadest meaning."
"Green Diary Rescue" will be posted every Saturday at 1:00 pm Pacific Time on the Daily Kos front page. Be sure to recommend and comment in the diary.