 So at the start of the Industrial Revolution in the mid to late 1800s, the amount of fossil fuels being burnt increased significantly. And around about the 1890s, carbon dioxide concentrations were starting to increase in the atmosphere. There's a bit of a flaking of the curve around the Second World War, but after that, with our increase in industrialisation and growth, the carbon dioxide concentrations have increased exponentially. Carbon dioxide is primarily absorbing the long wave radiation that's been emitted by the warm surfaces. So increasing the number of carbon dioxide molecules in the atmosphere results in more of this outgoing radiation or outgoing energy being rerouted through the Earth atmosphere system for longer. This means that the energy bounces around in the atmosphere before it eventually makes its way out and into space. From what we know about the physical processes of radiative energy and how it behaves in the Earth's atmosphere, it's just logical that there has been an increase in internal energy and we see that in the temperature trace. But what's interesting is that the average temperature of the Earth lags behind the carbon dioxide and the emissions graphs. And so this suggests that the response of the atmosphere to changing carbon dioxide concentrations is complex, the flexibility and the plasticity of the system. And here we have evidence of that. It took a little while before the temperature started to increase, so the Earth had the capacity to absorb some of that extra carbon dioxide, but we have now exceeded it.