The Climate Assessment Tool

The Climate Assessment Tool (CAT) is a free-to-use webtool which removes some of the uncertainty from trying to select tree species for a future climate that, at present, we can only imagine.

To do this, the CAT requires only 3 things:

» A location

» A tree species

» A selection of 1 of 3 climate emission scenarios

Mean Annual Temperature has been found to be a good proxy of environmental factors which influence plant health and mortality and is used as the key for scoring suitability. The CAT looks at records of known observations for the species, both in its natural distribution and in cultivation, and specifically at the MAT of the locations of those observations. It then compares the MAT of those observations to the MAT of the predicted future climates of 2050 and 2090, using emission scenarios laid out by the UN’s IPCC. By looking at the MATs of where a species is known to grow now, some insight can be offered as to how suited it may be to a location’s future climate.

There is always more to a plant’s success or failure than climate alone. Soil texture and chemistry, water and nutrient availability, competition, predation, microclimate, etc., all influence a plant’s health and performance. A scoring of red does not necessarily mean a species will not grow in a future climate, and for that matter, a scoring of green does not guarantee that it will, although the odds are definitely better.

The CAT is not intended to replace the many considerations of plant selection or be an absolute answer regarding climate suitability. However, as climate change progresses and historic horticultural observations and experience are no longer applicable, the CAT can be used in that stead. The future is unknown, but we are not entirely unprepared.

The CAT was developed by the Climate Change Alliance of Botanic Gardens, Botanic Gardens Conservation International, Royal Botanic Gardens Victoria, Dr Dave Kendal of Future Nature, with financial support from the International Association of Botanic Gardens. The CAT, along with guidance for usage and interpretation, can be found at http://cat.bgci.org.