Summary and Conclusion

In summary, the decline in sea ice observed in the early twentieth century is not abnormal when considering past reductions which have been shown to oscillate, however it is the recent several decades decline that cannot be identified in the last couple of thousand years. Evidence of earlier oscillations and reductions is not of high enough resolution to make such a claim but there is no evidence in support of such a decline either. As orbital forcing and mechanisms acting today have been proven to cause a reduction alone the true magnitude of GHG loading on sea ice reduction is unknown however very evident. At current the GHG loading level, which is forecast to increase and the positive feedbacks operating in the process sea ice is surely to continue declining. All of the forecasts predict the seasonal disapearance of sea ice which has many negative impacts across many contexts.  

This study does not discuss political and economic agendas to decrease GHG emissions and ultimately reduce there abundance, but is aware. The models all adopt emissions scenarios with increasing GHG loadings; however the outcome and influence of aforementioned agendas is unknown.

This study posits that a tipping point has been reached and that sea ice will seasonally disappear. Even if GHG loading does stabilise or even decline, the rate at which it will do so coupled with the ice-albedo positive feedback it will be too late. Therefore also this study highlights the need for up to date models which take into account the GHG loading decline