Ten days, four countries, 14 climate heroes, one incredible #ClimateRoadTrip. We traveled from Berlin to Paris using all kinds of environmentally-friendly vehicles, calculating our carbon footprint along the way.

But that's not all we did. The trip saw us climb an old coal excavator and a 16-meter-tall tree. In the pouring rain, we reached out over the rail of a boat to fish plastic out of Amsterdam's canals. We saw a wind turbine from the inside and a coal mine from atop. We met with Greenpeace, Germany's environment minister and a French delegate of COP21. And we got to know Europe's climate heroes.

Our mission was to highlight how regular citizens across Europe are fighting climate change in creative and often courageous ways, from occupying a forest in a bid to protect it from being cleared to make way for a coal mine to suing the Belgian government for failing to reduce its carbon emissions.

Here are 10 lessons we learned along the way.

1. Taking a bus is the greenest way of traveling over long distances

Over the course of the trip, we traveled 1,594 kilometers (almost 1,000 miles) using different modes of low-carbon transportation. We took e-cars, carpooled and rode trains and buses. In between, we biked, walked, took a jaunt in a solar boat and hung on for dear life in a bicycle rickshaw.

You might think bikes and solar boats are the best way to travel with a clear conscience. Neither emits any CO2. Still, they're not exactly practical for long-distance journeys. So what's the most environmentally-friendly way of getting around on long journeys? Taking the bus! That's because you share the CO2 emissions with so many people.

A ride on a public bus produces less than half the amount of CO2 than a trip on the train. The biggest climate culprit is flying. Jetsetters emit five times more CO2 per person than those who opt for the bus.

2. You don't need to be a 'big fish' to change things

Climate change might seem like an abstract, complex issue that's better solved by politicians. We tell ourselves: "There's noting I can do about it, governments will figure it out." We reassure ourselves that it won't affect us. None of that is true. Global warming affects every single one of us and it will take everyone to tackle it and make a difference.

This can happen away from the political arena. You don't need a big budget and state mechanisms behind you to change things. We can all do our small share to protect the planet.

"An ordinary citizen somewhere in a small village can contribute to something very positive for the climate," Jean Francois Julliard (pictured), executive director of Greenpeace France, told us. He believes the solution to climate change is people power - and not politics or climate conferences like COP21.

Schools of "small fish," who have decided not to wait for solutions from the government, already exist. They are regular people. Some are working to reduce waste by recycling plastic, redistributing wasted food or selling packaging-free food. Others are creating low-carbon transport or are investing in renewable energy. Some are even taking illegal routes to save the planet.

3. Some people are willing to go to prison for the planet

Would you risk going to jail to protect the climate? In Germany, a group of activists are willing to break the law - and even go to prison - to save Hambacher Forst, a 12,000-year-old forest.

German power company, RWE, bought the forest as it wants to expand the country's largest brown coal mine, Tagebau Hambach. To do that, it plans to clear part of the ancient forest. It has already chopped down large wooded areas and moved entire villages for its mining activities.

But a group of activists is determined to keep the diggers away. So they have given up everything they have and moved into the forest, building wooden treehouses in the ancient trees, where they sleep every night to prevent them from being cut down.

Some of their friends regularly sneak into the open-pit coal-mine, chaining themselves to mining excavators to disrupt operations for a few hours at least. It's not exactly legal but they're willing to take the risk.

"You have to do what feels right. I can't just sit there and do nothing while they cut down our forest," one of the activists told us.

4. You can sue your own government for failing to tackle climate change

Did you know it's possible to take legal action to fight global warming? Some European citizens are doing just that. Take Ignace Schops, for example. He is suing the Belgian government for not doing enough to combat climate change.

Together with a group of artists, filmmakers and even rock stars, Schops wrote an open letter to the government, asking it to cut CO2 emissions by 25 to 40 percent by 2020 and 87 percent by 2050. When the government failed to agree, the group took legal action.

Schops' climate case is still ongoing but he's hopeful of a win. After all, it's not the first time citizens have sued their government for failing to act on climate change and won. In Holland, a court ordered the state to cut greenhouse gas emissions nationwide by at least 25 percent by 2020 after an organization successfully sued the Dutch government on behalf of 900 citizens.

So, if you want to do the same in your country, here's Schops' advice: find a creative group of well-known people who can raise awareness of the cause; set up a petition to gather citizen support; and start a crowd-funding campaign to pay for legal fees. Now, you're good to go.

5. You can turn trash into treasure

Waste is something with no value that we can just toss, right? Not for some of the climate heroes we met on our journey. They showed us it's possible to do something useful with trash rather than just dumping it.

Take Marius Smit. For him, plastic is a resource we can use to create awesome things. So he decided to become the world's first plastic fisherman. He boats along Amsterdam's beautiful canals and fishes out the plastic bottles dumped there. He then uses these discarded bottles to build specially designed boats. That way, Marius helps to keep the canals plastic-free and is protecting the climate by reducing plastic waste. He's also helping people to understand that plastic is too valuable to be disposable.

6. Climate protection can be delicious

Changing people's attitudes when it comes to waste is something Luana Carretto is also trying to do. What motivated her? Seeing tons of perfectly edible food thrown away without a second thought. That's why she collects food Dutch supermarkets would usually bin at the end of the day - think misshapen vegetables, oddly colored fruit or holiday specialties like Christmas cookies dumped once the season is over.

You might be surprised just how much food is thrown away. Luana and 35 other volunteers pick up 350 kilograms every week - and that's in just one neighborhood in Amsterdam.

Luana gives some of the food to charity. The rest she uses to make people "taste before they waste," by organizing food markets, where she hands out free food, as well as by running community dinners for her neighbors. Their reaction to the wasted food speaks volumes: It's delicious!

The Amsterdammer wants to help people understand that the way we consume has a direct impact on our environment.

"Think about the amount of energy and resources that we put into the production of food, to fly it half-way across the world, only to then throw it away," she told us. "That's just ridiculous; it's not a sane way of relating to our resources. It's disrespectful towards all the people who go hungry every day and towards our planet. I find that unacceptable."

So the next time we want to toss food we think has gone bad, we'll taste before we waste.

7. You can use your own poop as fertilizer

Every day millions of people around the world literally flush away what could be one of our most valuable resources for growing food: our own feces. It turns out that when treated properly, human poop actually contains valuable bacteria that make soil more fertile. We met a community in Amsterdam that does just this.

De Ceuvel is a creative co-working space with 15 offices, each equipped with a composting toilet. Once the toilet is full, the tenants bring it to a larger composter so it has more time to do its magic before being tested on site. If the quality is up to snuff, it's put to work helping to grow food in the greenhouse.

"Then we eat the food that was fertilized with our own feces, we go to the toilet again, use the feces to grow more food and we close the circle. This place is really about closing the nutrient cycle," Guus van der Ven, who is responsible for keeping the community sustainable using green tech, told us.

8. You can turn a coal mine into a green festival haven

For decades, Gräfenhainichen in the German state of Saxon-Anhalt was a coal mining region. But in the past few decades, it's become a green festival haven. At Ferropolis - or the city of steel - music fans can now dance in front of huge steel excavators which tower over the festival stages like dinosaurs from a time gone by.

And that's not the only cool part. Thies Schröder, CEO of Ferropolis, has devised a concept to make the festivals there as environmentally friendly as possible.

The parties are powered almost entirely by solar energy, which isn't an easy task if you think about how much electricity a festival's elaborate sound and light systems gobble up. What's more, the up to 25,000 festival guests are encouraged to arrive by train, not by car. Plus a "green campsite" and vegan and regional food are helping pave the way to a greener festival future.

9. It's really hard to travel with an electric car in Germany

If you think it's easy to travel with an electric car in Germany, think again. This may be a country that loves its cars but that affection does not yet extend to vehicles that run on electricity. We learned this the hard way.

Our first lesson: It's an odyssey in itself trying to rent an e-car. Hardly any car rental companies in Germany offer them. And those that do have a long waiting list. Like, really long. So long that you might need to book an e-car at least a month in advance. Even if you do manage to get one and want a one-way hire, you'll be disappointed. Not happening.

Our second lesson: Most e-cars will only go about 40 - 60 kilometers before the battery runs out. That's kind of a problem because it takes eight hours to fully recharge and it's really difficult to find a socket to do the job.

That brings us to our third lesson: The charging infrastructure for electric cars is really poor in Germany. For Berlin's 3.5 million inhabitants, there are only 190 e-car charging stations. Paris has 1,286. So if you don't live on the ground floor or own a very long extension cable, you have a major problem.

10. There's no legal enforcement for climate treaty cheats

The 21st United Nations Climate Conference, COP21, will take place at the end of 2015 in Paris. It's all about negotiating a new treaty to regulate greenhouse gas emissions and to save the planet before it's too late. The hope is that all 196 UN members states will sign a legally binding and universal climate change agreement.

But if it wasn't hard enough to get all of the world's nations to agree on a common climate treaty, there aren't any legal enforcements to ensure signatories stick to their promises.

"We don't have any police or international sanctions or green helmets that will be coming for these countries. There is no international court for the environment," says French COP21 delegate Philippe Lacoste.

According to Lacoste, countries would lose their credibility if they don't stick to the treaty. "Nations are morally obligated to fulfill promises made," he said. We'll see how that goes. If worst comes to worst, we citizens may have to sue all of our governments.