Some like it hot... but not this hot!

Bob Spicer
Normally solitary, giant squirrels are
rarely seen together except about
breeding time.

For the past week or so the daily maximum temperature in Lucknow has been above 40 °C. Yesterday it was 42°C, and more of the same is forecast for the next five days. In these temperatures the demand for electricity to power air conditioning units exceeds supply and we have experienced frequent outages sometimes lasting hours. Without electricity to drive pumps, the water supply also fails.

It is sobering to think that in a warming world such events are bound to become more commonplace, not just here but across all the lower latitudes. We in the UK will not be immune either as summer heatwaves like that of 2003, which claimed so many lives across continental Europe, are forecast to increase in frequency and severity.

To help improve those forecasts we have been working on improving the warm climate performance of a technique that uses leaf architecture as a proxy for temperature and rainfall. By applying this technique to fossil leaves we can better quantify ancient climates, many of which were warmer than now, and thereby learn how climate might behave in the future.

Recently I sampled six forests in Kerala, south India. At a latitude of around 9.5 °N they are well within the tropical zone, yet unlike many low latitude areas, they also experience marked variations in rainfall due to the influence of the Asian Monsoon. They never really dry out though, and so those lush forests host a large number of leeches that make sampling leaves a somewhat bloody affair. Apart from leeches the forests also support a rich variety of animal life such as giant squirrels (Ratufa indica), deer, and even wild elephants. Although Kerala promotes itself as a “green” state there are precious few undisturbed forests remaining. Most have been destroyed to plant tea and the destruction continues as multinational corporations have the power to buy up land and overpower conservation efforts. Soon there will be very little natural vegetation left save for a few protected reserves, with a consequent loss of biodiversity. Of course Kerala is not alone in losing its unique heritage this way, but it is particularly depressing to witness it first hand.

Bob Spicer
Tea plantations replace natural forest diversity, leaving only a few remnant trees as witnesses to what once was

Leaves from each of these modern sites are numerically scored and analysed using a technique called CLAMP. Results so far show that all the Kerala sites form a coherent cluster in a new area of what we call “physiognomic space” and thus provide opportunities for recalibrating CLAMP for low latitudes, both now and in the past.

This is exactly what we were hoping for. Now I am in the process of collecting and collating decades worth of weather observations for these areas so that the calibration process can take place. At least I will continue to do that if the power stays on and the computers don’t overheat.