BERN, SWITZERLAND – Hazelnut trees began to bud throughout Switzerland 15 December 2015, the earliest since records have been kept, more than 150 years. Meteoswiss published information this week about the early budding and other signs that warming is happening earlier and earlier. A number of plants are showing leaves a week earlier than in the past.

Last year, 2015, was the warmest on record worldwide, with temperatures in Switzerland averaging 1.29C higher than during the previous 30 years. The trend continued when 2016 began: the 2015-16 winter is 2.5C above the 1981-2010 average.

Meteoswiss notes that while this means our weather is changing, it does not necessarily indicate climate change, which can only be measured over a far longer period. The weather service also points out that not all plants are reacting the same way to warmer temperatures coming earlier: while hazelnuts promptly start to bud, elm trees appear to have a protection mechanism that stops them from reacting just to temperature rises.

The weather service, ETH in Zurich and Globe Switzerland have set up a joint public-academic-government service to record plant life changes as part of a larger effort to track climate change. PhaenoNet, the service, has invited the public to help it record hazelnut changes in Bern as part of the programme, starting in March 2016.