Thunberg and thousands of protesters marched across the streets of Lausanne, Switzerland, to call for environmental protection

17-year-old environmental activist Greta Thunberg joined thousands of protesters in Switzerland today, days before the start of the Davos summit of the world's political and economic elite.

"Until this decade, we still don't see signs of real environmental activism. That needs to change. This is just the beginning, people still haven't seen anything. We promise about that, "Thunberg told the cheering crowd supporting her.

Protests today have blocked the roads of downtown Lausanne. The crowd gathered at a branch of Credit Suisse, a financial group criticized by protesters for investing in fossil fuels.

The group of protesters chanted environmental slogans like "No planet B", "I have a green dream" or "Let's change the system, don't change the climate."

Thunberg is expected to appear at the Davos summit next week, calling on the government and financial institutions to stop investing in fossil fuels.

Greta Thunberg became famous globally after dropping out of school to work in the environment. The "6th Day for the Future" movement spread to many countries, attracting millions of students to participate.

Many people supported Thunberg, but there were many ideas that her message was extreme and caused confusion. World leaders like Trump and Putin also disapprove of her actions, saying she thought it was "too simple".