THERE'S a monster sycamore tree at the end of my garden, over a hundred years old, and over seventy feet tall, and next door's garden has a younger silver birch, elegantly stretching more than fifty feet high. They are made of carbon, and I often wonder how much.

Trees tuck away about 22 kilos of carbon annually so that an average mature one contains one tonne of carbon, made from three and a half tonnes of CO2.. That will do for the birch, but I suspect the sycamore must be three tonnes, if not more. While this may not sound too impressive, as each one of us in the UK produces about nine tonnes of CO2 every year, enough for a biggish tree, we need to remember that there are billions of trees world wide, at the moment – we are well and truly outnumbered.

And there were once many more. About half the natural tree cover has been removed since 1500, and satellites show that deforestation is still happening, often illegally, and not only in the tropics. As well as beetle infestations, caused by warming temperatures, and wild fire losses, the demand for biofuels, and soya and maize for animal feed threatens many current forests.

There's been some progress with the recent arrest of the Brazilian master mind illegally removing parts of the Amazon rain forest, and the Forest of Bradford reached its half million planted trees milestone last year, on its way to double that number. However it's too easy to remove trees that are deemed inconvenient, as Saltaire residents were reminded recently.

It's estimated that deforestation adds about 16 percent of the CO2 added to the atmosphere each year, and this is more than from all forms of vehicles, three times more than flying and just less than rearing animals to eat. And it all matters because there is a limit to the level of CO2 in the atmosphere if we wish to keep the temperature rise below two degrees, the danger level when all sorts of other problems, like serious sea level rise, destructive storms, and crop and water failure wreak havoc.

That level is one trillion tonnes of extra CO2, that is 1,000,000,000,000 tonnes, and we're more than half way there, with over 588,000,000,000 already produced. Last year we added another 40,000,000,000 tonnes and at that rate it will be bingo in 2035, in less than 20 years.

We can only avoid the trillion tonnes target if we start reducing the CO2 emissions by almost three per cent a year, starting to-day. In 2014 they increased by almost that amount.

The website - beat.org.uk - shows how to help Bradford plant more trees.