Why is it so cheap to offset carbon emissions?

Many people are confused by the low price when offsetting carbon emissions. If it’s so bad for the environment to fly, can a few dollars really be enough to counteract the impact? The answer is yes. At present there are all kinds of ways to reduce emissions very inexpensively. As an example, a low-energy lightbulb, available for $2 or so, can over the space of six years save 250kg of CO2 – equivalent to a short flight. That does not mean that a low-energy lightbulb make up for flying. The point is simply that the world is full of inexpensive ways to reduce emissions. In the future, when more people and governments starts to offset, the price of offsets might gradually rise, as the low-hanging fruit of emissions savings – the easiest and cheapest “quick wins” – will get used up. Read more here: https://www.theguardian.com/environment/2011/sep/16/carbon-offset-projects-carbon-emissions