timeline for a disintegration is 1000 years after the tipping threshold is crossed, while it is far more likely to take place over 10,000 years; the longest possible estimate is 15,000 years. It had also estimated that due to the ice-albedo feedback, a total loss of the ice sheet would increase the global temperatures by , while the local temperatures would increase by between and . Meltwater run-off Meltwater around Greenland may transport nutrients and organic carbon to the ocean. Measurements of the amount of iron in meltwater from the Greenland ice sheet show that extensive melting of the ice sheet might add an amount of this micronutrient to the Atlantic Ocean equivalent to that added by airborne dust. However much of the particles and iron derived from glaciers around Greenland may be trapped within the extensive fjords that surround the island and, unlike the HNLC Southern ocean where iron is an extensive limiting micronutrient, biological production in the North Atlantic is subject only to very spatially and temporally limited periods of iron limitation. Nonetheless, high productivity is observed in the immediate vicinity of major marine terminating glaciers around Greenland and this is attributed to meltwater inputs driving the upwelling of seawater rich in macronutrients. The United States built a secret nuclear powered base, called Camp Century, in the Greenland ice sheet. In 2016, a group of scientists evaluated the environmental impact and estimated that due to changing weather patterns over the next few decades, melt water could release the nuclear waste, 20,000 liters of chemical waste and 24 million liters of untreated sewage into the environment. However, so far neither US or Denmark has taken responsibility for the clean-up. A study published in 2016, by researchers from the University of South Florida, Canada and the Netherlands, used GRACE satellite data to estimate freshwater flux from Greenland. They concluded that freshwater runoff is accelerating, and could eventually cause a disruption of AMOC in the future, which would affect Europe and North America. A 2018 international study found that the fertilizing effect of meltwater around Greenland is highly sensitive to the glacier grounding line depth it is released at. Retreat of Greenland's large marine-terminating glaciers inland will diminish the fertilizing effect of meltwater- even with further large increases in freshwater discharge volume. A 2015 study by climate scientists Michael Mann of Penn State and Stefan Rahmstorf from the Potsdam Institute for