In the last few days, there are increasingly frequent discussions about the direct consequences of climate changes on various nations, changes we are witnessing with our own eyes. They represent a reality nobody can deny, because you don’t necessarily need to be a scientist to perceive their influence, increasing from one year to the next, and challenges are multiplying for the authorities that need to adopt measures, on one hand for cutting polution, and on the other hand for facing the costly events caused by global warming. Therefore, the European Council has established, in October 2014, the three objectives that will grant direction to the action of the European Union regarding the struggle against global warming in the next few years. These objectives are valid for Romania as well, and involve both the research and the adoption of concrete measures. For each of these member states, these measures include the adoption, starting in 1990 and ending in 2030, of a decrease of gas emissions causing greehouse effect by at least 40 per cent, an increase in the use of renewable energy up to 27 per cent of the energy mix and the improvement by 27 per cent of the energetic efficiency of the country, as well as the reduction of energy intensity measuring the amount of energy necessaeity to produce an added value unit (or its positive equivalent). To find out more about climate changes in the times to come and about their effect in Europe and Romania, I discussed with Roxana Bojariu, the coordinator of the climatology department of the National Meteorology Administration, part of a team of authors who had ellaborated the Fourth and Fifth Report of the Inter-Government Group for the Study of Climate Change (IPCC).
Roxana Bojariu, a graduate in Physics at the Physics Department of the University in Bucharest (1984), is the coordinator of the climatology section at the National Meteorology Administration. She gained a doctor’s degree in Global Physics at the Physics Department of the University in Bucharest, in 1999. In 2005, she won the Stefan Hepites Award of the Romanian Academy. She was a member of the lead authors team that elaborated the Fourth and Fifth reports of the Inter-Government group for the Study of Climate Changes, published during 2007 – 2013. During the last 20 years, she coordinated Romanian teams in eight scientifical projects financed by the European Commission. She is a member of Ad Astra Association that reunites Romanian researchers in the country and abroad.
Ms. Bojariu, you are an expert in climate changes. What can you predict about the climate changes in the next 50 years, based on the data you have?
According to estimations based on several numeric experiments, presented in the Fifth Report of the Inter-Government Committee for Climate Changes published in 2013, the average global temperature will increase by over 1.5 Celsius degrees by the end of the 21st century, compared to the period 1850 – 1900, in three of the four scenarios referring to the increase of greenhouse effect causing gas concentration in the atmosphere. In the initial two scenarios, that predict a higher increase in the concentration of greenhouse effect gas, by the end of the 21st century, the growth of the world average temperature is likely to exceed the limit of 2 Celsius degrees, which means that the impact on ecosystems and the human society may exceed their adaptive capacity, and lead to unpredictable impact on the geosystems. The amount of rainfalls and their global configurations are due to change by the end of this century, with creat regional differences due to increase contrasts of humid and dry regions. The changes already noticed in the case of sea ice and continental icebergs will continue and amplify during the next decades. Predictions regarding the level of the global ocean suggest increases depending on scenario, of 0.2 to 0.55 metres in the most optimistic of them and of 0.45 to 0.82 metres in the most pessimistic of them – based on the highest increase in the concentration of greenhouse gas – yet, experts did not exclude values exceeding these estimations – due to insecurities on mechanisms affecting the ice coating of Greenland and Antarctica. The results of numeric models, presented in the IPCC reports published in 2013 suggest a different consequence of global changes: the intensification of the hydrological cycle. This intensification may determine an increase in the intensity and / or in the frequency of extreme events, such as floods, that occur fast in many regions of the globe. Other extreme phenomena, such as heat waves, will occur with increased frequency, will be more persistent and more intense on the continents.
How will Europe – and especially Romania – be affected by the climate changes? What should we expect in this part of the world?
Global warmth in Europe will bring challenges related, on one hand, on the increase of air temperature over the global average value and, on the hand, on the contrasts of the future regime of rainfalls in nordic regions, where they will register an excedent, and the South of the continent, where the vulnerability to drought, already present, will increase much more. In Romania’s case, the average temperature will increase in all seasons and regions, with regional differences in the size of this increase, given by local factors – such as, by example, the presence of the Carpathian mountains and the neighbourhood of the Black Sea) In the case of average temperature in summer months, this increase could reach up to six Celsius degrees, in the worst case scenario related to the increase in the concentration of greenhouse effect causing gas. Numeric experiments also show a decrease in the amount of rainfalls in Romania for the warm season months. In the worst case scenario mentioned above, the reduction of rainfalls on Romanian territory might reach up to approximately 30 per cent by the end of the 21st century – 2071 – 2100 – compared to the value of reference 1961 – 1990. It is not just the average values that will change, but also the statistics of extreme phenomena, as this change will cause an amplification of risks related to natural disasters – fast floods, waves of heat, droughts, fires in the forest. The frequency of heat waves increased and will continue increasing in the next decades precisely in South-Eastern, Southern and Western regions surrounding the Carpathian chain. Urban agglomerations in these regions will experience the increased weather-related stress due to the urban island heat effect. On the other hand, the results of numeric experiments suggest us that episodes of great amounts of rainfalls will be increasingly frequent, especially in mountain areas. Under the circumstances of accelerated deforestation, this increase in the frequency of events with a massive amount of rainfalls will cause an increased incidence in fast catastrophic floods.