Results of a long-term survey indicate that spring is arriving in the Arctic weeks earlier than it did a decade ago. Rising temperatures are causing snow to melt sooner, extending the summer period and dramatically disrupting the fragile(壊れやすい)ecosystem. Scientists recorded a clear shift in the time of year plants flowered, birds laid their first eggs and insects emerged to forage(食料を入手する)for food. This is one of the most rapid examples of climate change, indicating a global trend of warming.