The difference between weather and climate is important, but trends in weather can be symptomatic of climate change. While one day of cold does not mean climate is cooling and one hot day does not mean climate is warming, if the trend is that average temperatures keep increasing, and do not decrease or return to whatever your normal is defined as, or go beneath that normal, then you are possibly observing climate change in the form of global warming.
If it turns out you have warming averages over a period of 50 years or so, and most of the hottest years in recorded history have occurred in the last 20 years, then you can go and look to see if you have confirmatory evidence of climate warming.
- You might look to see if glaciers are contracting, which they seem to be.
- Polar ice caps also seem to be shrinking or thinning, so much so that people are even talking about sailing near the north pole.
- Hot days seem to be more frequent and are coming in strings rather than as disconnected events.
- Days over 45 degrees C might have once been rare but are now not that rare and come together. You may even see days of 50 degrees which previously did not occur.
- Droughts seem to be increasing in hotter areas of the world.
- We have forest fires all over the world which are often described by fire fighters as unprecedented, and previously rare fire behaviours seem to be becoming more common (at least they are where I live).
- Some forests which we don’t think have burned for thousands of years have burnt, even if they were isolated from other fires.
- Coral reefs are suffering large scale bleaching, almost certainly from heat.
- Tropical fish are reportedly moving away from the equator…
If you look you may find further evidence suggestive of climate change.
Then you might ask what evidence is there for the idea that climate change is not happening? Is there any evidence of increasing cold, more glaciation and so on? Is there evidence climate is not changing, other than assertions climate scientists are lying, because it cannot be true. Not very much I can see, but you would expect some uneven weather behaviour given weather is a complex system.
To me, it looks as though global warming is occurring. The next question is, “Is this a problem?”
Some people may assert that heat is good. Well yes it is, up to a point. Humans find it difficult to work outdoors when its over 45 degrees C, they are also more likely to die of heat stroke. Extreme heat usually means that water evaporates and goes somewhere else. Some rainfalls will decline, some will increase. That does not mean the change will be good. Humans only flourish within a relatively small temperature range. Deserts, hot or cold, are not easy to survive in, although people can if they have the right tech for a while.
More carbon dioxide might increase some plant growth, but it also harms some plant growth, it’s not simple, it may even depend on other factors such as soil nitrogen content. But even if it was simple, it is unlikely that plant growth will solve the problem of climate change, or increase food production by enough to compensate for the loss elsewhere, especially if the heat is killing the plants. Eventually evolution will sort this out. Plants will change, but that will take a long time.
More heat will almost certainly increase methane release from under frozen tundras, and this will add to the quick warming effects. It will compound the problem
Is Climate Change serious? I happen to think so, because rapid changes in complex systems generally produce wild instabilities as the systems attempt to find equilibrium amidst the disruption. Weather can be very destructive. Human societies seem to have collapsed previously with even mild changes of climate, so we need to exhibit care, not pretense that nothing important is happening, however nice it might be if nothing was happening.
We can predict global warming would happen as greenhouse gases increase. Indeed people have predicted this for a long while.
As far as I can see there is no real alternate explanations which check out (at the moment).
If the warming is created by the increase in greenhouse gas, there is no reason to expect that the trend of warming is going to go away without action to reduce those gases.
Therefore it seems sensible to me, to reduce those gases if at all possible, and reduce them quickly, before we get truly disastrous levels of climate change and have no hope of calming the system.
While other events could possibly happen and we could thrive under global warming, it seems foolish to depend on those other unlikely, and unforeseen, events happening.
It also seems likely that reducing fossil fuel use may well have other pleasant consequences. Fewer people might die of poisoning and particulate pollution. Less ecological damage would need to be repaired. Life would be cleaner. So why not embrace the challenge of dealing with the problem rather than running away from it?
Tags: climate change
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