The Idea: Set up benches with decarbonizing algae pools in sealed urban spaces.

In Serbia an extraordinary project has emerged: the liquid tree. This “Liquid 3” facility can achieve the air purification capacity of a full-grown tree or a 200 square meter lawn, says the start-up. This innovative solution can be particularly effective in densely populated cities where traditional trees hardly find space. The facility also serves as a bench for pedestrians. And I bet the gentle bubbling of the system provides a calming side effect, similar to an aquarium.

The Idea: Reforestation through gamification and education.

In Kenya, the government-created app Jazamiti encourages people to actively participate in tree planting. The goal: to plant a whopping 15 billion trees in 10 years. Users are categorized based on the number of trees they plant, utilizing classic social and gamification elements. This way, the app increases participation and offers both individuals and organizations the opportunity to get involved. Importantly, learning content is also included, such as which trees are particularly suitable for the climate region to avoid succumbing to heat in the future.

The Idea: Produce paper from fallen leaves.

If you move one level up in the value chain, it becomes clear that you wouldn't have to plant so many trees if you weren't cutting down so many. The Ukrainian start-up Releaf Paper transforms the paper industry by using fallen leaves instead of healthy trees. To produce one ton of cellulose, the start-up requires 2.3 tons of dry leaves — compared to the usual 17 trees needed for the same amount, so they say. This innovation could reduce deforestation and enable a more sustainable use of resources.

The Idea: Buoys generate energy through their up-and-down movement.

Swedish engineers have developed a technology that converts the power of ocean waves into electricity. The buoys utilize the principle of linear motion: waves move the buoys up and down, and a cascading gearbox converts this motion into rotational energy, which is then used for power generation. Even high storm waves pose no problem, underscoring the robustness and efficiency of this technology. One of these “buoys2.0” can produce about 1/30 of a modern offshore wind turbine at peak load, do the inventors state.

The Idea: There are many places for solar cells. On roofs, in fields, or as it turns out: on lakes.

In Germany, a study shows that the 6,043 artificial lakes in the country hold significant potential for floating photovoltaic systems. Currently, some systems are already installed, but the potential for more than a hundred times as much. This is primarily due to legal requirements i.e. that the installation must be at least 40 meters away from the shore. For example, in the Maldives, where there is little space for photovoltaics but plenty of sunshine, several projects exist. This type of energy generation can preserve valuable land space while simultaneously promoting renewable energies.