Climate change is connected to the carbon cycle. The carbon cycle is the process which regulates the greenhouse effect and makes life on earth habitable.
We need the greenhouse effect in order to survive on Earth. Without it, the planet would be around 30°C cooler and uninhabitable for humans. Yet by increasing the level of greenhouse gases released from activities like agriculture and the burning of fossil fuels, we are enhancing the effect and making our planet much warmer than it would otherwise be (source: WMO).
Scientists have discovered that human practices, particularly over the past two centuries, has led to human induced climate change.
It is also worth noting here that "overconsumption" is recognised by scientists as a major contributor to climate change - moving away from oil and gas isn't enough; we also must reduce our consumption of the planet's resources, because this also feeds into and exacerbates climate effects. It also affects our planet's ability to try to cool itself, as it does try to regulate itself, in turn affecting our planet's ability to regulate itself.