It is not dangerous with an increase in temperature of 2-3 degrees
An increase of the average global temperature with 2-3 degrees above pre-industrial time will have more positive then negative effects in many regions of the word. We have already a global temperature that is more then 1 degree above that during pre-industrial times. For the time being the global temperature is not increasing so fast then during the last 10 years, but these changes go in cycles and we expect that it soon will pick up again so that we can soon experience that w ego through the upper limit of 3 degrees, as accepted by the EU. Thus we could indeed agree with the above-cited statement.
However, the effects are unevenly distributed and while a rich country like Norway will not suffer others will. For example: the Sahel region, countries of the Arabian Peninsula or northern Africa. A global temperature increase is not a local and national matter, but a global one, i.e. the situation over the entire globe matters. The climate problem infiltrates a suite of problems, such as heath, politics, economy and security. All that has consequences for every country and every citizen. How will the World society react to immigration of climate refugees from regions that have become unacceptably hot? What about the advent of difficult to fight diseases such as malaria that is on the move into regions where it has long been forgotten to exist? An increase in temperature of 2-3 degrees is dangerous, if not for the region in which we live then as a consequence of the ramifications that a temperature increase has in other parts of the world. A global economy implies also enduring the climate effects of the entire globe.
It has also been warmer earlier and the climate changes whatever we do. What is so different today?
We have detailed knowledge from how temperature varied in previous times. We have a few continuous records since about 1850. We have investigations of tree rings growth for a few hundred years. We have data on the ocean temperature from sediment cores on a suites of time intervals, from hundred to several thousands of years. The longest record we have come from ice cores in Antarctica where we have detailed knowledge about temperature down to 900.000 PP. Most of these records do indeed show that there have been warmer and colder periods. However, the alarming signs are a) that the global temperature is now higher than during any interglacial time, b) that the final increase comes during a short time interval (100 years) and c) that the tendency over the last 30 years is ever increasing (with some variability). The conservative consensus of IPPC states that the warming this time is not only natural, but basically caused by humans. Many indices tell us that we should be in a cooling period, but we face basically the opposite (right now we have a slight decline).
In contradiction to former times when climate variation was natural IPPC thinks mankind can do something with it. This is because climate warming is caused for the most by emission of greenhouse gasses. Two of them, carbon dioxide and methane, have increased due to human activity with 38 and 148 % since the industrial revolution. There exists enough knowledge to take action, but out hesitation to do so, probably based upon our unwillingness to change our resource overconsumption, results in that climate warming increases further. Despite of setting an upper limit of + 2 degrees our lack of action implies that this limit seem to have become unrealistic already. Scientists have not been able to convince the general audience. Thus we, the people, do not comprehend the consequences of what we do. What is different today compared with other time periods is that warming is manmade. And these consequences, if not for us, then for people more exposed for warming. Our production of green house gasses should be accompanied by willingness to accept climate refugees, but I am afraid this is not the case.