Wanted any bright or crazy ideas on saving global environment

We are 2 months behind on a two week deadline for the Philippine robotics olympiad. I have two teams from two different schools (Claret School of Quezon City and International School of Manila) who will be participating in the open category. This year's team is "Saving global environment".
Global environment protection is a global theme of the future. It is important to approach this problem from a
scientific and technological perspective, particularly using robots.

Examples:

Prevention of Global Warming e.g.) Factory emission control of greenhouse gases, promoting the use of non-fossil fuel energy (solar power, wind power, etc.), electric energy consumption controlling devices.
Countermeasure against the acid rain problem, or measuring its impact on the environment.
Conservation of forests, especially prevention of deforestation and promotion of forestation.
Investigating the ocean and river pollution, and support its purification.
Investigating the cause of dinosaur extinction and its relativity to global climate change.
Informing the people what they can do in their daily life to save the environment.
Spreading the "MOTTAINAI": A Japanese word introduced to the world by Prof. Maathai of Kenya at the UN. This is the underlying mentality of the Japanese Eco-culture. (What a waste! )
Development of robot technologies taking part in environmental conservation.

In line with this, my team from Claret created a diorama of Boracay beach. A popular tourist destination in the Philippines. We are going to build our robots based on what we can do to help preserve the beaches, environment and surrounding sea of Boracay. We also need to find ways on how to develop renewable energy.

For team ISM we choose to build a green city. We came up with a scale model of a condominium unit, streets, parks, and a river. We will find ways on how to recycle, minimize pollution and find alternative means of energy.

Any bright ideas would be highly appreciated. We also accept crazy ideas. Who knows they might just be the solution to the problems we are facing today. We will be using Lego RCX and NXT robots.

Thanks,

Rox