Read the passage carefully and choose the correct answer.
Viet Nam Likely to Face Extreme Weather Conditions by 2050
Viet Nam is likely to continue facing extreme weather conditions such as higher temperatures, lower summer rainfalls, stronger storms, and rising sea levels from now to 2050. Temperatures in northern Viet Nam will rise by between 0.83 degrees Celsius by 2050 and continue its uptrend during the late 21st century. Summer rainfall will decline in most areas. Meanwhile, storms may become rarer but fiercer, causing possible flash floods and landslides in flood-prone areas of northern mountainous, central and central highland provinces. The forecasts suggest sea level rises of 100mm - 400mm along the entire Vietnamese coast by the end of the 21st century, affecting marine biodiversity and coastal communities. The experts emphasize the unpredictability of climate change and its potential impacts to create a variety of dangerous extreme weather events in the future. To raise the public awareness of climate change impacts, the Vietnamese government urges concerned agencies to work together on devising worst-case scenario models and responses by 2020 and calls on international experts to further support Viet Nam in climate change adaptation. Climate change is a real threat to Viet Nam’s socio-economic development. If sea levels rose one meter, five percent of the country’s land, eleven percent of its population and seven percent of its farmland would be affected.
Question: To experts, they ______ to predict exactly the model of the climate change and its potential impacts.