1.4 C may not sound like much, but small changes in the global average can mask more dramatic localised disruptions in climate. Some changes will be global: we can expect sea levels to rise by as much as 0.9 metres, effectively rendering a huge proportion of what is now fertile coastal land uninhabitable, flooding low-lying cities and wiping out a swathe of shallow islands worldwide.
The principal culprit is carbon dioxide, a gas that even in quite small quantities can have a dramatic impact on climate, and has historically been present in the Earth's atmosphere at relatively low concentrations. That was until human activity, including burning fossil fuels, began raising background levels substantially. Yet while we're bracing ourselves to deal with climate change, we also face soaring demand for more energy - which means burning more fossil fuels and generating more greenhouse gases.
