- throughout the month The Tree Council's Walk in the Woods: Trees Matter - Enjoy Them
- 4 - 10 Compost Awareness Week
- 19 - 23 May Walk to School Week
- 19 - 23 Noise Action Week
- 19 - 25 National Vegetarian Week
- 20 Protest vigil outside the House of Commons, calling for a halt to airport expansion and immediate and real Climate Action Now, organised by we CAN a group of concerned mothers and young people.
- 31 Demonstration at Heathrow, Called by Campaign against Climate Change, HACAN, NOTRAG , and others.
- May 31 - June 21 National wildlife week
- International Year of Planet Earth is a 2008 international observance, declared by the 60th United Nations General Assembly. The Year's activities will span the three years 2007-2009. / Earth
- International Year of the Potato
- International Year of Sanitation
- 2005 to 2014 United Nations Decade of Education for Sustainable Development / Education
- 2005 to 2015 Water for Life Decade / H2O