Healthy heart, healthy earth
Gyms with machines that are designed to capture energy instead of use it
What actions do you propose?
So much potential energy is wasted and more damage is created by fitness gyms which use a lot of electricity.
With health and fitness becoming more popular - what if people could feel great in their bodies AND hearts and minds, knowing that they are producing energy for the community as they run, pull or pedal? 
Who will take these actions?
I think this could be started by grassroots social enterprises and will generate a lot of support from various places
Of course there needs to be engineers  involved but also anybody who can offer can help: trello  and whatleadsto  are great platforms for such collaboration
I also think existing gyms may wish to convert slowly!
What are the key challenges?
Loads, we all know the IPCCs projections for business as usual. It's about collective responsibility 
What are the key benefits?
People's wellbeing improving is always good and socio-cultural awareness of sustainability and unique ways to achieve a better world can be inspiring.
What are the proposal’s costs?
Well, I think that initial investment into green technology will be substantial but returns will come very quickly as ethical consumption is becoming more popular and holistic wellbeing also!
2. Development of Network (needs online platform too)
3. More outreach
Timescale depends on interest level. But it's part of larger processes. Socio-cultural change, collective responsibility for planetary concerns!
Related proposalsValue not set.
Already been done successfully in other places: lets establish a global network!