Summer sea-ice melt in the Arctic is already the second-meltiest since satellite records began, and by the end of the melt season in mid-September, this year could surpass the all-time record low set last year, according to scientists at the National Snow and Ice Data Center. For the second time ever — the first being last yearthe Northwest Passage shipping route is open and ice-free this year. What’s more, Arctic sea ice appears to have reached “a tipping point” from which it may not recover; the Arctic is now expected to be entirely ice-free in summer by 2030. Arctic sea-ice melt typically begins to slow in August as temperatures get cooler, but this year, just when it was expected to slow down, the melting sped up, giving this year’s melt an ominous shot at breaking the record. But regardless of whether this year is officially a record-breaker or not, it’s clear to researchers that the Arctic is unwell. “No matter where we stand at the end of the melt season it’s just reinforcing this notion that Arctic ice is in its death spiral,” said Mark Serreze of the NSIDC.