Weather is created out of changing heat and cold of the landmass and the oceans during each day and with the seasons. We are now making profound modifications to these ancient systems through general warming and the imbalance between equatorial temperature rise and polar - some 3°C.
2005 was the second warmest year on record increased by accelerated melting of Arctic sea ice and Siberian permafrost. In the oceans this has been exacerbated by the disruption of the global ocean current that warms Europe and the growing permanence of the El Nino in the Pacific.
Climate models have been suggesting for years that the equatorial and southern regions will become dryer, with many areas moving into permanent drought. This includes some of the poorest lands in the world where people are least able to adapt, and some of the most populous. This is climate change in a big way!
Excessive amounts of freshwater from melting Arctic ice would alter the ocean density that drives the Gulf Stream, thus diminishing the amount of heat carried northward, and significantly cooling the northern hemisphere
Hurricanes and cyclones
Catastrophic storms and hurricanes will become more frequent and more destructive as the oceans heat up. Evidence is building up at an alarming rate as we read of more extreme weather in all parts of the world, such as Katrina.
Since the 1970s, ocean warming had made hurricanes about 50 percent more intense in the Atlantic and Pacific oceans as the mid-Atlantic and the Caribbean have warmed significantly.
It is expected that the strongest hurricanes of the last few years will be upstaged by even more intense category 5 events with Katrina-intensity becoming the norm.
The trend is there: Last year 3 major hurricanes and 5 tropical storms hit the US. The last time there were eight such catastrophes in a single season was 1916. There were ten typhoons over Japan where the previous record was five. It is expected that Sydney will meet its first cyclone thundering down the coast in the near future.
See Meg Howe's site: Wakeup2GlobalWarming.
Global warming is shoving jet streams out of their normal tracks. They zip along at altitudes of about 10,000 metres at the boundary between warm, tropical air nearer the equator and cooler air closer to the poles. The temperature difference generates many of the earth's winds and storms.
Over the past 30 years these high-speed air currents have shifted about one degree toward the poles, or about 120 kilometres. This movement is evidence of massive changes to atmospheric circulation. If the jet streams continue to migrate away from the equator, wide swathes of the planet will become hotter and drier.
Earlier climate models have been too simplistic for the intricacies of nature. There has been unexpectedly rapid heating in the subtropics (at 30 degrees north and south) whereas the models predicted a more uniform warming. These regions, which already have warm climates, include north Africa and the southern regions of China, Australia and South America. This will bring widespread drought to these areas.
The consequences of weather uncertainty are hard to quantify, though here is an indicative list.
Consider how each of these outcomes would impact on you personally:
- Flooding from storms and exceptional rainfall impacts most heavily on the more fertile regions created from floodplains. City food supplies are restricted or become very expensive, as happened recently with Australian stone fruits and bananas.
- Sea surges will massively affect low-lying regions where there are dense populations, from the China coast to Florida. Many of these are retirement havens.
- Mud slides where there has been heavy deforestation, most often near shanty towns where there has been minimal regard for potential collapse. More involved as most of the population increase is migrating to new suburban sprawl.
- Dry equatorial weather ignites increasingly huge forest fires that destroy a lot of the timber used in construction, as well as creating smoke haze and affecting health.
- More extensive drought that will become permanent in some areas, and will effect the major grain-growing areas of Argentine and Australia.
- Dry conditions encourage swarms of pests, such as locusts, and wood-eating beetles to move into fertile areas.
- Heat and fire melts more permafrost, and this destabilises roads and buildings, leading to emigration.
- Extensive loss of stock and crop from all the above with huge consequences for those in marginal food areas. Some cultures, such as those in central Asia and east Africa that count their animals as wealth, will disintegrate.
- Increasing risk makes it harder to obtain insurance, and therefore less infrastructure and fewer assets are properly rebuilt leading to a serious undermining of services and standards.
- Millions, and ultimately over a billion people are displaced by ongoing catastrophic events and the resulting hunger.
The number of humans on the planet grow in step with all the risks all these humans are creating.