evidence: NSIDC scientist Mark Serreze published a study in 2018 indicating that spring melt seasons have started earlier and continued for a longer period throughout the year. This conclusion was based on examining the long-term satellite record dating back to 1979. Even more disquieting, NSIDC scientist Julienne Stroeve published a study in 2007 comparing actual Arctic sea ice decline to the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) projections, showing that observed ice loss is faster than any of the IPCC AR4 models have predicted. Stroeve and colleague Dirk Notz of the Alfred Wegener Institute in Germany published a study in 2016 indicating that under the Paris Agreement limiting global warming to 2°C (3.6°F), Arctic sea ice will almost inevitably disappear during summer. But the summer ice can likely be saved if warming is limited to 1.5°C (2.7°F).