With all the debate and worry about climate change, why don't you play a part in the study of its effects on the environment?
In the UK, The Woodland Trust and the UK Phenology Network (phenology is the science behind how climate influences changes in annual events like bird migrations and plant growth) have teamed up to run Nature's Calendar. Relying on the observations of thousands of volunteers, they collate the information gathered and compare it with records dating back to the seventeeth century to produce long-term analysis of the effects of climate change on our flora and fauna.
It is free to register as a volunteer, although as it costs around £10 to equip every recorder and process their results you will be asked for a donation. You will get a guide to spotting the various species and form (you can also log your results online). For example, the kinds of things you will be looking for in spring are first sightings of new growth on trees, first flowerings of plants, first sightings of birds, insects, butterflies and amphibians.
Children can also get involved, with a similar program specifically for them called Nature Detectives: Nature Detectives.
Go to Nature's Calendar for more information and to sign up.
Wikipedia has more information on phenology and opportunities for recording data in other countries around the world: Wikipedia: Phenology