Chapter 1 - Life on planet earth
Increasing concentration of greenhouse gases in the atmosphere raises the surface temperature. Human activities can contribute to the greenhouse effect and thereby affect the climate. This is the background to today’s alarming reports about the warming of the planet.
Carbon dioxide emissions dominate the greenhouse effect – representing about 75 percent of the effect by their warming potential.
These emissions must be eliminated or reduced as quickly as possible. But it is not possible to ignore other issues; to drastically reduce economic activity by choice is not an option grounded in reality. The challenge is balancing the needs and time perspectives of different stakeholders, and creating incentive systems that address the distributional aspects.
Is it even sensible to talk about such a change?
What is the alternative? The authors’ conclusion is that we must move in this direction, and that is what this guide is about. What possibilities we have, in which time perspectives, and how the choices we make along the way can eventually lead us to what we are calling the “1-tonne society”.
If we are unable to keep warming below two degrees during this century, we will be looking at even greater challenges.
The roof that keeps us warm
Greenhouse gases act like the roof of a greenhouse, keeping the heat from escaping into space. Without this effect Earth would be uninhabitable. Human activities increasing the concentration of greenhouse gases in the atmosphere contribute to the greenhouse effect and thereby affect the climate.
The Carbon Cycle
The problem can be described as the movement of carbon from “deposits” (fossil geology, soil and plant life) to the atmosphere at an accelerating rate. This is partially mitigated by the fact that the oceans absorb about half of the carbon that is released. However there are questions as to how long they will be able to play this mitigating role. This is one of many “tipping points” under discussion – changes that can dramatically alter either the warming process itself or other natural conditions for life on earth.