“It’s 2019. Can we all now please stop saying ‘climate change’ and instead call it what it is: climate breakdown, climate crisis, climate emergency, ecological breakdown, ecological crisis and ecological emergency?” [Greta Thunberg]
Vietnam is one of the countries that will be most affected by climate breakdown; here Peter Baker looks at how it is already affected and the part that coffee is playing in it.
Average surface temperatures in Vietnam have warmed by 1°C over the last 40 years. Warming varies widely across the country with the southernmost region of the Central Highlands and Central Coast provinces increasing the most.
Current monthly July-August temperatures in those provinces are over 5°C warmer than long-term averages and significant trends in rainfall are correlated with areas with a very high proportion of agricultural land. Specifically, the main farming area in North Vietnam is experiencing a significant decline in rainfall whereas the country’s largest agricultural production area in the South is undergoing both significant increases and decreases in rainfall according to location.
In the coffee zones of the Central Highlands, a recent HRNS study likewise found very high rates of warming (especially in the dry season) and a mixed picture for rainfall, but with a surprising overall shift in the wet season, which has progressively started and finished earlier by 2-4 days per decade since 1980.
Droughts are related to the El Niño phenomenon which hit the Central Highlands with particular severity. Even a moderate episode in 2002-3 reduced coffee production by about 25 per cent. But the 2015-16 event was the most serious in living memory with main river discharges reduced by up to 90 per cent.
By mid-April 2016, nearly 170,000 hectares of crops were drought affected, including coffee, though this did not greatly depress national coffee production due to the widespread use of irrigation, which buffered the event. However, the groundwater table, normally about 10m deep, fell as low as 70-80m, with reports of boreholes created up to 120m depth and surface water pumped in from up to 10km distance.
Local and regional causes
Hence the pattern of change in the Central Highlands and Vietnam is diverse, with some localities warming much faster than average and surprisingly varied rainfall patterns.
This phenomenon is now commonly seen in tropical zones and scientific studies increasingly link it to widespread deforestation. Large forests create their own climate, causing evaporative cooling as well as contributing significantly to inland rainfall through massive evapotranspiration.
When major deforestation occurs, even if replaced by crops and agroforest, evapotranspiration declines and temperatures increase. No studies exist for Vietnam but a recent study in Borneo showed a strong relationship between forest loss and recorded increases in daily temperature and reductions in daily precipitation.
This effect is most pronounced for watersheds which, like Vietnam, have lost 40–75 per cent of their forests over the decades since the 1970s .
Modelling supports such observations, including a study of deforestation over Indochina which suggests strong effects on rainfall distribution.
Further afield in Brazil, dry season changes in Rondônia have been correlated to deforestation and results of modelling in the Amazon basin confirm the effects on local rainfall . Accordingly, there is now acute concern among climatologists that the extent of Amazon deforestation (now about 20 per cent) may be reaching a tipping point towards a permanently drier climate.
What Vietnam’s climatological record reveals – localized rainfall changes, zones warming much faster than national or global averages – is entirely consistent with changes caused by widespread deforestation. All stakeholders in Indochina should now be extremely concerned that the region’s heavy deforestation over the past 50 years will play a prominent role in future climate breakdown.
Responses to the climate crisis
Adaptation: pioneering work by D’haeze showed that coffee farmers irrigate excessively – up to 1,000 litres per tree per round, whereas <500 litres was sufficient to cause no yield loss.
Work by HRNS has promoted the training of farmers to use less water. Encouragingly now, international coffee companies have agreed to address environmental issues for coffee with IDH Sustainable Trade Initiative, Dutch and Vietnamese governments signing an agreement in April to reduce water, fertilizer and pesticides use and protect natural forests in coffee production areas in Vietnam.
An IDH funded field study carried out by Agri-Logic in the Central Highlands also showed that farmers can combine coffee and fruit crops like avocado and durian in an agroforest arrangement without coffee yield reductions, hence increasing resilience, especially during times of low coffee prices.
Mitigation: since the Paris Agreement, nearly 80 per cent of countries involved have declared their intention to promote agricultural practices to curb climate change. This has triggered a number of initiatives, including studies on the role of farms to sequester additional CO2. A new study finds that Central Highlands coffee agroforestry is the most cost-effective alternative of all agricultural interventions.
However, the amounts of CO2 that could be sequestered are small. Even if all Vietnam’s coffee were converted to coffee-fruit agroforestry, the additional gain would be only about 0.2 million tons CO2e/yr.
Forest cover in decline
If this seems a lot it should be compared with the output from the additional 13GW of coal-fired power stations that China is currently building in Vietnam, of which coffee agroforestry could absorb less than 0.5 per cent of those added emissions. Even if all 41 agricultural options listed in the study were implemented – an extremely unlikely eventuality given the costs – they would absorb less than 80 per cent of this additional coal plant capacity.
Deforestation: national forest cover declined from ~43% in 1943 to 16–27 per cent in 1993 and then steadily increased over recent years, but secondary regrowths are low density with poor biodiversity.
Monocultures of fast-growing exotic species make up approximately half of the forest area increase in Vietnam. Rates of clearance of Central Highlands natural forests increased during the period 2005-2009 compared to 1999-2005, while natural forest expansion in the rest of the country slowed down.
Most of the recent reforestation in Vietnam was thus due to increases in plantations. Despite apparent efforts by authorities to control deforestation, the many reports by VietNamNet Bridge strongly suggest they have been ineffectual. Additionally, there are credible reports of substantial and corrupt importations of hardwood forest timber from across the Cambodian border.
Further warming is inevitable, with a 1°C global increase possible by 2050. How this plays out over the Central Highlands region is difficult to predict, especially changes in rainfall patterns, drought frequency and intensity.
It is very likely however that there will be more extreme events with ever hotter El Niño episodes and ever stronger downpours. But the Central Highlands is not the most threatened region: the Mekong delta has suffered both from severe drought and sea-level rise which has caused salt-water intrusion (up to 80 km inland in 2016) and major crop losses. Net outward migration is increasing and it is likely that this will put the Central Highlands under growing pressure as a bastion against extreme lowland degradation. The situation is worrying and despite fairly small-scale initiatives and a recent recognition from the National Coffee Association in the US that deforestation is an issue for coffee, few are the signs that the coffee industry is taking the situation seriously, either in Vietnam or all other coffee countries.
Adaptation: farmers risk being in a state of perpetual recovery between price and climate shocks. Carry out extensive agroforest trials to determine ways to partially diversify without reducing coffee yields. But don’t pretend that agroforestry will contribute materially to sequestration.
Mitigation: protect the regional hydrological cycle in order to ameliorate high temperatures, encourage high regional evapotranspiration and thereby encourage rainfall to recycle across the region.
This entails a major effort to stop deforestation not only in Vietnam but across Indochina – a huge task that the coffee industry alone cannot achieve. But it could play a catalytic role by commissioning work to determine the technical feasibility and cost of accurately recording in real time deforestation, be it by satellite, drone and whether registered by AI or citizen science. NGOs like MAAP and Global Forest Watch have shown the way.
A concerted effort could also determine true size of the global coffee park and determine coffee’s global footprint.
Above all, by blowing the whistle on countries that continue to freely deforest, the iconic coffee industry could finally justify its often over-hyped claims to sustainability.■ C&CI
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This article first appeared in the July’19 issue of C&CI. Click on subscribe now if you wish to read more informative articles in the current and future issues of C&CI.