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Hot-spots & recent change Identification of climate change hot spots and risks in specific regions, particularly Minas Gerais PS Baker R Ruiz Belo Horitonte, 9th September 2013


How do we know what is happening? At the farm/district level? • We know the climate is changing globally • But we don’t know how this is manifesting itself at the local level – there are major regional variations • We have climate maps that project future climate change – global, regional, some for coffee – up to 2050, 2100 • These are important for strategic understandings • At a local level however these are not enough for extensionists and the many farmers who are facing difficulties now


How do we know what is happening? At the farm/district level? • It’s a problem for the c&c initiative, which is trying to identify and prioritize risks • We cannot help all farmers everywhere prepare for all possible CC risks • We have to focus • To objectively quantify the present climate/weather situation locally as much as possible


Example: E Africa projected to get wetter

• IPCC 2007 Projections for 2080-2099


But in reality it has been getting drier (Funk et al USGS)


Future rainfall is especially a problem • We know it will get warmer • But precipitation is much less certain for any given locality – Wetter? – Drier? – Both (at different times of the year or longer period)? • Very difficult to approach farmers about future flood risks if their recent experience is drought


Dealing with uncertainty • What we need are accurate indications of how things have been changing in the recent past • We use this as a guide to the present and the near future (and compare it with models) • There is no ideal solution, but we believe it to be the best strategy • But we have a practical problem


User-friendly historical weather data is mostly lacking! • We need easy to understand maps that show coffee-relevant met. data – E.g. to indicate zones getting drier – E.g. zones where maximum temperatures are getting higher

• This sort of data does not exist – it’s a major failing – agrometeorology is not user-friendly • So we are having to do it ourselves • I.e.: turning data into info & knowledge


So we commissioned a study Ramiro Ruiz (Uni Belo Horizonte)

• Meteorological data used from 79 stations and 264 rain gauge locations, from 1960 – 2011 • Quality control procedures included: – Screening to identify erroneous data (e.g. Tmin > Tmax, negative precipitation, etc.). – Identification of temperature outliers using standard deviation thresholds. – Statistical gap-filling of missing temperature data – Homogeneity tests to detect data incontinuities


So we commissioned a study Ramiro Ruiz (Uni Belo Horizonte)

• Minas Gerais Jan-Mar rainfall (mm) • 1961-1980 Rain mm


So we commissioned some work Ramiro Ruiz (Uni Belo Horizonte)

• Minas Gerais Jan-Mar rainfall (mm) • 1981 – 2011: Getting drier in NE of Minas Rain mm


MG – temperature • Mean max temp for Sep- Nov (a critical period for flowering (get increasing flower abortion > 32°C) T mean max


MG – temperature rises • Mean max temp for Sep- Nov (a critical period for flowering (get increasing abortion > 32C) T mean max


MG – temperature rises • Mean max temp for Sep- Nov (a critical period for flowering (get increasing abortion > 32C) • Getting hotter in north MG T mean max


For the first time… • We have a simple visual way of seeing recent CC – and we think this is the best way to orient adaptation options 1995 coffee production T mean max

2011


Absolute maximum temperatures (Tmax) Statistically significant increases over MG

• Significant positive trends for the annual count of days with Tmax greater than 32oC (SU32). • Stations at the southern region had a 5.56 (± 2.9) days per decade increase • Zona da Mata (2.35 ± 1.8 days per decade ) at Caratinga and Viçosa).

Filled triangle = significant increase in Tmax


Daily temperature range Has been linked to coffee quality

• DTR = Monthly mean difference between Tmax and Tmin • A mixed picture, but going up in Sul de Minas Filled red triangles = significant increases


Signs of heavier rainfall events in parts of SW MG • R50mm: annual count of days when precipitation greater than 50mm

Filled red triangles = significant increases


Annual water deficit in Minas Gerais 1960-1985 and 1986-2011 periods 1960 -1985


Annual water deficit in Minas Gerais 1960-1985 and 1986-2011 periods 1986 -2011


Mean annual water deficit by region in 1960-1985 and 1986-2011 periods

-183.5 mm -249.1 mm

-40.4 mm -51.2 mm

-195.8 mm -270.5 mm

-85.8 mm -103.1 mm


Summary • This practical, user-friendly but science-based approach can give us some insight into local, recent climate change • Especially where it coincides with model projections, it gives us considerable confidence to develop longterm strategies and help farmers make the right adaptation decisions (short to long term) • We think this is the best way to guide us about what tools to use and where • It is an approach that we would like to develop in all coffee-growing countries


Identification of cc hot spots and risks in specific regions RRC FUMG