Net-zero emissions means reaching a stage where the Earth is carbon or climate neutral, and where emissions of CO2 and other GHGs do not exceed a finite emissions budget for a given level of global warming. This is achieved through balancing the amount of emissions released to the atmosphere with an equivalent amount being sequestered (see CCS) or offset (see carbon offsetting). Net-zero emissions leave some room for continued but significantlly reduced emissions, as long as they are balanced out by increasing natural carbon sinks (e.g. by planting trees), using technical solutions to remove CO2 from the atmosphere, or buying enough carbon credits to make up for the difference (see also CCS and Emissions trading). The IPCC says that in order to limit warming to 2°C, CO2 emissions from the energy sector need to fall to zero by between 2040 and 2070, falling "below zero" thereafter. While net-zero emissions can continue, they need to be balanced with negative emissions technologies.