"Every bit of warming matters"
"A great achievement of the Paris Agreement was the submission by almost all member governments of the Climate Change Convention of their Nationally Determined Commitments (NDCs) until 2030"
In your opinion, what did the Paris Agreement mean?
The Paris Agreement was a recognition of the need to strengthen the global response to the threat of climate change to limit warming to a level that minimizes impacts to natural and human systems, particularly of the more vulnerable populations. A great achievement of the Paris Agreement was the submission by almost all member governments of the Climate Change Convention of their Nationally Determined Commitments (NDCs) until 2030. Although in aggregated numbers the present NDCs are not compatible with limiting global warming to 1.5 ºC or less than 2 ºC, it already represented the awareness that climate change can have consequences to all sectors and livelihoods and that there is still a window of action to limit warming.
2 ºC is not enough. IPCC points to 1.5 ºC with its special report "Climate Warming of 1.5 ºC". Why?
One of the key messages of the Special Report was that every bit of warming matters and that significant differences exist between a 1.5 ºC warmer world and a 2 oC one. These differences include increases in mean temperature in most land and ocean regions, hot extremes in most inhabited regions, heavy precipitation in several regions and the probability of drought and precipitation deficits in some regions. As one example, the projected sea level rise at 1.5 ºC at the end of this century is 10 cm lower than that at 2 oC, and this could mean 10 million fewer people exposed to related risks (based on population in the year 2010). At 2 oC, coral reefs are practically extinct whereas at 1.5 ºC a small percentage still survives.
What main conclusions would you like to highlight from the latest IPCC study?
The main conclusions can be summarized as follows:
(1) Human activities are estimated to have caused global warming of approximately 1 oC above pre-industrial levels and impacts on natural and human systems have already been observed. Many land and ocean ecosystems and some of the services they provide have already changed due to global warming.
(2) Every bit of warming matters -climate-related risks for natural and human systems are higher for global warming of 1.5 ºC than at present, but lower than at 2 oC.
(3) Addressing climate change goes hand in hand with other policy goals, such as the Sustainable Development Goals (SDGs) of the Agenda 2030 for Sustainable Development. 1.5 ºC pathways have robust synergies with several SDGs, including health, clean energy, cities and communities, responsible consumption and production and oceans.
The IPCC acknowledges nuclear power as a source with low carbon emissions. What do IPCC studies indicate regarding nuclear?
Nuclear energy plays a role in most pathways that limit global warming to 1.5 ºC, as indicated in the SR1.5, and increases from pathways with no or limited overshoot to those with high overshoot. The last assessment report of the IPCC (AR5) already indicated the role of nuclear as part of low-carbon electricity supply portfolio to achieve low-stabilization levels. In the majority of low-stabilization scenarios in AR5, the share of renewables, nuclear and Carbon Dioxide Capture and Storage increases from the share of approximately 30% in 2012/2013 to more tan 80% by 2050, and fossil fuel power generation withouth CCS is phased out almost entirely by 2100.
"Addressing climate change goes hand in hand with other policy goals, such as the Sustainable Development Goals (SDGs) of the Agenda 2030 for Sustainable Development"
Do you think we must use all emissions-free energy sources currently available to tackle the climate problem that humanity is facing?
Based on our understanding of the response of the climate system, stabilizing global warming at 1.5 ºC requires CO2 emissions to reach net zero by mid-century and a decline in other non-CO2 human emissions. Rapid and far-reaching transitions in energy, land and ecosystems, urban and infrastructure (including transport and buildings), and industrial systems would be required. These systems transitions are unprecedented in scale and imply deep emissions reductions in all sectors, a wide portfolio of mitigation options and a significant upscaling of investments in those options. Taking the energy system transitions as part of the mitigation portfolio, all low-carbon primary energy sources, including renewables, nuclear and fossil with Carbon Dioxide Capture and Storage have a role to play.
"Nuclear energy plays a role in most pathways that limit global warming to 1.5 ºC"
Do you consider that we are gaining increasing awareness with movements such as "Youth for Climate"?
Definitely these movements have an impact on public awareness of climate change as a threat to future generations. Depending on the actions taken now, the world in the future might be completely different and might compromise livelihoods and ecosystem services. The movement shows leadership of the youth on climate change issues and this is much needed.