It's very difficult to have a positive impact in the world beyond your everyday actions or your business reach, but here are some inspiring examples of grit and determination and vision.
Thanks to carbon credits, which companies purchase to offset their emissions, 2.2 million people - about 25% of Rwanda's population - are about to get clean water and energy.
Evan Thomas, an engineering professor at Portland State University, is spearheading a project where 2000 residents of Rwanda will distribute water filters and efficient cookstoves to about 750,000 households by next spring.
Dirty water causes the vast majority of disease in Rwanda, where the life expectancy is under 50 years old. Worldwide, contaminated water kills 1.5 million children every year.
Burning wood to cook inside the home pollutes indoor air, causing human disease, while destroying forests and sending particles into the atmosphere - one of the key climate change forcers.
Read: Controlling Black Carbon Soot Emissions Could Cut Rate of Climate Change by Half
About 500 of those filters and cookstoves will have a remote smart sensor that Evan developed in his lab. They will answer two questions: Does the technology work, and do people use it?, he says.
Most international development projects rely on costly in-person spot checks, making it difficult to collect enough reliable data to prove a project's success.
Each sensor has five AA batteries which will power it for a year while it measures usage and performance. Cell phone waves send data to a web-based platform, where the results directly inform any adjustments to the technology or educational efforts on the ground. Portland State engineering students helped develop the sensors and will analyze incoming data.
He received $550,000 to commercialize the remote sensors - known as SweetSense - in partnership with Oregon BEST, the Lemelson Foundation, Stevens Water and Mercy Corps, all based in Portland. Portland State co-owns the sensor technology with Stevens Water, where SweetSense will carve out its own production area once the devices go to scale.
Evan hopes the significant health and climate improvements will demonstrate the potential to deploy and monitor international health programs like this on a very large scale.
Pretty impressive - he implemented a similar effort in 2011 that covered 877,000 households in Kenya.
Another important effort in Mozambique is bring cooks stoves that run on locally produced ethanol.
Goldman Environmental Prize
This year's 6 fearless environmental leaders receive their $150,000 prize today for working against all odds to protect the environment and their communities.
Now in its 23rd year, the prize goes to grassroots environmental heroes from each of the world's inhabited continents.
The winners receive their prize - the largest in the world for grassroots environmental activism - tonight at the San Francisco Opera House.
Caroline Cannon, USA
Caroline Cannon is bringing the voice and perspective of her Inupiat community in Point Hope to the battle to keep Arctic waters safe from offshore oil and gas drilling.
Ma Jun, China
Ma Jun is working with corporations to clean up their practices with an online database and digital map that shows Chinese citizens which factories are violating environmental regulations in their country.
Evgenia Chirikova, Russia
Challenging rampant political corruption, Evgenia Chirikova is mobilizing her fellow Russian citizens to demand the rerouting of a highway that would bisect Khimki Forest, Moscow's "green lungs."
Ikal Angelei, Kenya
Risking her life, Ikal Angelei is fighting the construction of the massive Gibe 3 Dam that would block access to water for indigenous communities around Lake Turkana.
Edwin Gariguez, Philippines
A Catholic priest, Father Edwin Gariguez is leading a grassroots movement against a large-scale nickel mine to protect Mindoro Island's biodiversity and its indigenous people.
Sofia Gatica, Argentina
A mother whose infant died as a result of pesticide poisoning, Sofía Gatica is organizing local women to stop indiscriminate spraying of toxic agrochemicals in neighboring soy fields.