2018 demonstrates extreme weather's impact on development

31 August 2018

Written by Regina Asariotis, Chief, Policy and Legislation Section, UNCTAD

Following 2017, one of the warmest years on record that included the most costly hurricane season contributing to the highest documented economic losses (approximately $ 320 billion) due to weather and climate events, the first half of the summer of 2018 was also marked by extreme weather, including record temperatures, heatwaves, droughts, wildfires and devastating rainfalls.

In fact, 2018 might be on a record-setting path as the hottest La Niña year to date, according to the World Meteorological Organization.

These recent experiences and observations bring to the fore, once again, the potential impacts that weather and climate-related extreme events may have.

Recent research projects substantial changes in several climatic factors, with potentially important implications not only for a plethora of agricultural and industrial sectors, but also for global trade and for the sustainable development prospects of the most vulnerable nations, including SIDS, LLDCs and LDCs.

extreme weather

In terms of health-related impacts, currently nearly one-third of the global population is regularly – at least 20 days per year – exposed to “deadly heat” conditions due to the combination of high temperature and relative humidity. By 2100, this percentage is projected to increase to 48% under a scenario with drastic reductions of GHG emissions and to 74% under a scenario of growing emissions, with developing countries in tropical and sub-tropical zones facing greater exposure.

In addition, extreme precipitation and extreme sea levels are projected to increase very substantially, resulting in coastal flooding that will pose high risks to the dense populations, infrastructure and assets of coastal areas across large swathes of the global coastline.

Recent research suggests a very likely increase of the global average 100-year extreme sea levels of 0.34 – 0.76 m under a moderate-emission-mitigation-policy scenario and of 0.58 –1.72 m under a ‘business as usual’ scenario between 2000 and 2100. From 2050 onwards, under these scenarios, large swathes of the tropics will be exposed annually to the present-day 100-year event, whereas by the end of the century this could be the case for most of the global coastline, implying unprecedented flood risk levels unless timely adaptation measures are taken.

Climate-related extreme events and disasters are projected to also result in significant economic costs. A recent study indicates that, by 2100, global flood damages due to sea-level rise (and related extreme events) might amount to up to $ 27 trillion per year – about 2.8% of global GDP in 2100.

The situation is likely to be worse for small island developing states (SIDS) exposed to tropical storms. For example, Dominica’s total damages and losses from hurricane Maria in 2017 have been estimated at $1.3 billion – about 226% of the country’s GDP. And losses for Anguilla, Bahamas, BVI, St Maarten, Turks & Caicos following hurricanes Irma and Maria have been estimated at US$ 5.4 billion.

While agriculture, tourism and infrastructure are some of the trade-related sectors considered to be particularly vulnerable, severe economic impacts of climate-related extreme events may also arise as a result of climate-related delays and disruptions to international trade and transport across a network of closely linked global supply chains.

With over 80% of world merchandise trade (by volume) carried by sea, international shipping and seaports are key to global trade-led development. Climate-related extreme events could have significant implications for seaport infrastructure, operations and services, with important repercussions for global sustainable development prospects and particularly for coastal developing countries and other vulnerable groups of countries.

SIDS already face several transport-related challenges as well as natural hazards and are particularly exposed due to their climate, geographical and topographical features as well as their critical reliance on coastal transport infrastructure, in particular seaports and airports. Climate-related extreme events affecting coastal transport infrastructure are likely to exacerbate existing challenges, making effective adaptation action an urgent imperative.

The particular exposure to climate variability and change (CV&C) of seaports and coastal airports with potential ramifications for trade has been highlighted by the recent vulnerability assessment of two Caribbean SIDS (Jamaica and St. Lucia) carried out by UNCTAD.

The results of the assessment of eight coastal airports and seaports, which focused on operational disruptions and marine inundation risk under different climate scenarios, suggest severe CV&C impacts on coastal transport infrastructure and operations. The assessment showed that these vital coastal transportation assets of both SIDS will face rapidly increasing coastal flooding risks due to sea-level rise and future extreme events. In addition, it was found that transport operations will also be affected, as the projected increases in the frequency of hot days will likely decrease the airport staff ability to work safely outdoors, require reductions in aircraft payloads and lead to increased energy costs:

  • Outside working conditions: By the early 2030s, staff working outdoors at the Jamaican and Saint Lucian international transportation assets could be at “high” risk for 5 and 2 days per year, respectively. By 2081-2100, such days could increase to 30 and 55 days per year, respectively.

  • Aircraft take-off: By 2030, Boeing 737-800 aircrafts will have to decrease their take-off load for 65 days per year at Sangster International Airport--SIA and 24 days per year at Norman Manley International Airport- NMIA (both in Jamaica), whereas by the 2070s such days could increase at least twofold for SIA and fourfold for NMIA, assuming no targeted aircraft design changes.

  • Energy needs: a 1.5 °C temperature rise will increase energy requirements by 4% for 214 days per year for Jamaican seaports, whereas a 3.7 °C rise (2081-2100) will increase energy requirements by 15 % for 215 days per year. Saint Lucia seaports are projected to experience similar trends.

Predicted climate-related impacts may cause major disruptions to the connectivity of both SIDS to international markets as well as to related economic sectors, such as tourism exacerbated by the projected beach erosion. Due to the strong nexus between transport infrastructure and tourism – the main driver of many Caribbean SIDS’ economy accounting for between 11 and 79 % of their GDP – the climate resilience of these assets is of crucial importance.

At the same time, important gaps remain in terms of data availability and information needs, as well as current levels of resilience and preparedness among seaports worldwide, as revealed by the UNCTAD survey Port Industry Survey on Climate Change Impacts and Adaptation. Relevant information and adequate climate adaptation efforts are therefore urgently required for the purposes of effective climate risk-assessment and adaptation planning of coastal transport infrastructure, especially for ports in developing regions.

For information on how Caribbean ports may adapt to climate change, visit