Well I watched this NatGeo doco re this very subject about climate change etcetera, did anyone else see this doco?
Man, this planet is full of surprises! They had three or four experts (and yes, they were) give their opinions on what our weather is doing at the moment and what's likely to come in store for us in the future.
It's all bad i'm afraid.
One professor in the US is the world's leading authority in Glaciology and recently uncovered some fascinating data. They drilled and withdrew an ice core sample 2KM long and inspected this long tube. What they found was a history of this plant's weather patterns over the last 150,000 (yes, thousand) years!.
The earth's weather at the moment in 'not natural' they have observed. The weather the plant has experienced for the last 10,000 years is actually a 'freak of nature'. The earth does in fact have hot and cold cycles - ie - very warm conditions throughout or freezing in the northern hemisphere.
Canada experienced a taste of this freezing cycle in 1998 which lasted just over 3 days. The temperature dropped 18 degrees from the normal average temp in summer. What happened was chaos. One of their two main power grids shut down, their power line towers collapsed under the weight of the ice, airports, infrastructure failed for that week. They said that if the freeze had continued longer it would have taken years for the city to recover.
They concluded that cities with high infrastructure will fall first because so many people rely on everything to live - unlike the poor souls in starving Africa say.
Several things contributed to this freezing condition on the planet.
Firstly was the orbit the earth takes around the sun. The last recorded world freeze was somewhere around 890BC - where everything died off. The earth apparently does not always orbit the sun in a perfect circle. Every 10,000 years its orbit widens to an oval shape taking us further away during that time from the sun - hence cooling of the earth's surface.
Second culprit: Volcanoes. They found that large volcanic activity actually cools the earths surface from the sulphur ash that is pumped into the air during eruptions. Sulphur mixed with water droplets looks like tiny mirrors - multiply that a trillion times and you have one large mirror deflecting the sun's rays back into space. It does not happen over months, it can take years for the affect to take place somewhere on the plant after the eruption.
They also said that it's not just the ash either that causes this reflection - ANY sulphur gas from volcano vents, large lava flows and pyroclastic flows will do this. They said that volcanoes are probably the second biggest threat to the climate apart from the global ocean conveyor current.
The global ocean conveyor is a current that encircles the globe and transfers warm water to the poles and so on - keeping an equalibrium effect. They have discovered that when the ocean conveyor slows it does not 'pull' the warmer water around the globe. Fresh water is not as dense that sea water - small amounts can be circulated, but large amounts cannot and can slow the current. Because of all the above circumstances, including global warming, more and more of the polar caps are melting and adding too much fresh water to the conveyor. If this continues - and they say it is happening right now - there will be widespread freezing conditions to more parts of the globe within 20 years.
Now that might sound like scaremongering - well it is and it's fact.
They global conveyor can only handle a certain amount of fresh water to circulate, if it get's too much then the warmer water becomes 'still' and slows the current and the weather patterns will obviously change drastically with that.
The thing is we can't stop it. No amount of reducing greenhouse emissions will be soon enough to halt the ice packs melting within a reasonable amount of yearly time period. Sure, it will help, but while volcanoes, ice caps melting and the planet orbits further away, there's not a lot we can do about all this except plan ahead.
We can't replace ice packs and shelves that have been solid for thousands of years and expect that if we reduce emissions by 60% in the next ten years the ice packs will reform - bit late i'm afraid - the melting has been going on for the last 10 years buddy!
The earth has its cycles and what we've been experiencing is just not a 'normal' cycle of this planets weather patterns. It's normally either hot or cold - simple. It's just that because man has studied the weather patterns since we've been able to we think we know it all. Well, i'm afraid dust, ash, bones and grit frozen in a time machine called ice tells us very differently. Every 10,000 years the planet goes into freeze mode and that timeframe is just about up!
Let's hope they're wrong because it won't be pretty.
Mike
