Jane Burston, head of Climate and Environment at the National Physical Laboratory, explains why the Paris Climate Deal will only work if we standardise the process by which emissions pledges are measured, reported and verified
Consensus was finally reached in Paris in December with 195 nations agreeing a deal to tackle climate change. Nations have agreed that the rise in global temperature caused by greenhouse gases is to be kept "well below" 2°C, the point when global warming would pose a threat to life on Earth. This will be achieved through Intended Nationally Determined Contributions (INDCs) – pledges to reduce emissions – from each individual country
Yet, before the event was even over various climate think tanks claimed that even if they are met, the INDCs committed to so far will only succeed in halting global warming at 2.7C above pre-industrial levels. What’s more, INDCs are not binding under international law, meaning individual countries will be responsible for meeting their own pledges, and each will be collecting data in a different way. This is no time for negativity – the agreement is still a triumph for international diplomacy and environmental awareness – but a clear knowledge of the data, what it shows and why is key in producing a clear picture of worldwide emissions.
The next logical step, therefore, must be to standardise the process by which emissions pledges are monitored. This is the only way to see the INDCs monitored and fulfilled across the board.
Standard models of emissions measurement use a bottom-up approach, which estimates emissions based on activity data (for example, electricity consumption in kWhs) multiplied by an "emission conversion factor" (for example, the amount of carbon dioxide attributed to the use of one kWh of electricity). These factors are established using direct measurements, but some countries do not have the means to make these measurements and hence rely on unsuitable data from elsewhere. Also, emissions from some sectors are very variable and it is hard to be sure that the measured emissions factors apply to all scenarios. In agriculture for example, uncertainties in emissions from livestock or fertilizer use can be greater than 50%. If we are to ensure the various INDCs are met, we need to improve on this, and provide support for developing countries to make their own measurements that are applicable to their particular circumstances.
There are now various emissions measurement methods that all come with a range of sophistication, accuracy levels and costs. They range from a low-cost portable remote infrared imaging system that can be use to detect the source of leaks, right up to Differential Absorption LIDAR (DIAL), a mobile facility capable of monitoring the concentration, volume and source of atmospheric pollutants remotely at ranges of up to 3km.
Ground-based methods can be partnered with regional networks of sensors that measure atmospheric concentrations of greenhouse gases, and with monitoring from satellites, which can give a global view of emissions.
Such a mixture of methods is the best way to ensure appropriate direct measurements are done. These will help nations achieve the required uncertainty levels when reporting on emission limits as per their INDCs.
The Paris Deal has given us a real opportunity to make huge inroads into reducing global warming, and we must be sure to make the most of it. The political will is there, and the technology to implement it is established. All that remains is a standardisation of robust MRV systems if we are to ensure that the INDCs are fulfilled and that the ultimate goal of keeping warming below 2°C is achieved.