In my youth back in the late 1970s and early 80s, I did a BSc in Earth Sciences. That gave me a sense of geological time where a million years was a relatively short period of time. It also made me realise that the human historical framework of decades and centuries was but a blink of an eye.
Finding that massive geological processes resulting from human activity are happening within my lifetime gives me a major sense of temporal discontinuity. The Met office in the UK are predicting the warmest 10 years globally since records began in 1850.
Which is a correct but limited view. It is going to be the warmest that it has been in hundreds of thousands of years. We’re heading for global temperatures that our planetary home hasn’t seen for 10’s of millions of years.
Those teeny red dots on the right of the this logarithmic time graph show temperatures relative to the expected average world temperature of 1960-1990. About 2 degrees Celsius in 2050, and 4 degrees in 2100. I suspect that both of these are conservative estimates. After all they are based on the conservative IPCC reports which only includes estimates of climate change process in their reports when the evidence is pretty overwhelming.
What many people seem to fail to realise is just how much our species is a direct product of the ice age we have been in for the last 40 million years when Antarctica started to glaciate at the south pole. It dropped the world into another long fridge period.
Starting about 3 million years the world started to get significiant glacial periods largely as a response to orbital patterns. That was when we evolved as a species.
Over the last 10,000 years after the last glacial, in a period of extraordinary climatic stability, we managed to develop a civilisation capable of supporting an extraordinary population growth spread over the whole world.
When I was born in 1959, the world’s population was about 3 billion. Now it is close to 7.5 billion. Most of that population growth is dependent on food grown using farming techniques based on relatively stable climates. That climatic stability for food production won’t continue as the extreme weather from shifts in climate keep impacting.
The World Meteorological Organization (WMO) has published an analysis of five major international datasets showing that the 20 warmest years on record have been in the past 22.
“Temperatures are only part of the story. Extreme and high impact weather affected many countries and millions of people, with devastating repercussions for economies and ecosystems in 2018,” said WMO Secretary-General Petteri Taalas.
“Many of the extreme weather events are consistent with what we expect from a changing climate. This is a reality we need to face up to. Greenhouse gas emission reduction and climate adaptation measures should be a top global priority,” he said.
BBC via Radio NZ
Other researchers in the field said the new forecast for the next five years was in line with expectations, given the record level of CO2 pumped into the atmosphere in 2018.
Currently in human time frames, this is a slow ongoing disaster. It shows in the shifts in weather patterns causing heatwaves, flooding, and fire around Australia and NZ. But also in the freezing in recent decades in the northern hemisphere as cold air from the Arctic gets pushed south as the winds around the north pole change. It is a basic bit of science that slogan fixated idiots like Donald Trump clearly fail to understand.
More heat in the climate drives more extreme movements in the air, and the oceans. And it is all happening so damn fast that there are no obvious references in geological history. No-one is really sure exactly what is will happen as climate change continues to accelerate. And accelerate it will.
All of the existing scientific estimates on the effects of climate are just that – estimates based on conservative and sparse data. The only thing that is consistent in the development of the scientific estimates of climate change over the last 4 decades is that the best estimates have consistently under-estimated the rate of change.
While this is going to cause problems for various parts of humanity as they get burnt out, flooded out, washed out, or frozen as the climate shifts. Similarly there will be farming disasters like the recent droughts followed by floods in Queensland that are suspected to have killed half a million cattle last week. That isn’t where the real problems lie.
We are unlikely to have the kind of catastrophic failure in the biosphere in the next centuries that is so beloved of dystopian movies. Insurance premiums and hardening against foreseeable risks will shift the more stupid behaviors like living and farming on flood plains or at the very edge of oceans (or below existing sea levels!).
But the disruption, famine, and disease that shifts in climate and weather patterns bring are the classic causes of breakdowns in human political systems leading to wars and direct societal disasters. That is what we need to really need to harden our civilisation against.