Most gardeners would agree that we have seen some rather odd climate changes in recent years and many would put that down to the impending threat of global warming. Scientists estimate that the world has seen an average increase of only 0.8 degrees Celcius and that much more is to come unless drastic action to cut greenhouse gas emissions is taken on a global scale. Even if we cut emissions, more warming will occur as the oceans form a great heat reservoir that delays the effect of the greenhouse gases that are being emitted today. So what has this all got to do with gardening?
Agriculture and the associated services that go with it actually account for 17% of energy use in the UK – that’s even more than transport services. Within this, the growing of plants is a very low proportion of the figure – most of it comes from processing, packaging and getting the goods to their destination. In fact, it has been estimated that for every calorie of energy in our food, an average of ten calories of fossil fuel energy has been used to produce it.
The keeping of livestock is also a much more energy-intensive process than growing food. Cattle use about ten times more water and land than the production of equivalent vegetable food sources and the methane gas that comes from them is estimated to contribute to just under 2% of all global warming (as methane is a much more potent greenhouse gas than carbon dioxide). There are other problems with animal farming as well: 38% of grain produced worldwide is fed to animals –shocking, when you consider how much of the world lacks stable food supplies.
So it will come as no surprise that the more environmentally-aware campaigners are now promoting home vegetable growing as one of the most positive things you can do to reduce carbon emissions. In so doing, we can cut out transportation and packaging of food, cut our intake of livestock-derived foods and eat more healthy, organic diets. If done on a wide scale this could free up land for re-forestation.
But will such measures really have any effect on global warming? Until very recently I thought not – after all, what can a lot of well-meaning gardeners do about a global problem? But then I read some interesting thoughts on the subject from well-know climate change author Patrick Whitefield. In a recent article in Permaculture Magazine he says: "If you look carefully at any trend in government policy you’ll see that it’s actually a response to a significant proportion of the population voting with their feet...a large minority, all of whom vote, by acting together can cause governments to change direction, and often have in the past." I don’t think we are at that point yet but no-one can deny the huge swell of public interest in climate change, organic growing and the benefits of home-grown produce. Perhaps gardeners will have more influence on the response to global warming than anyone has yet anticipated...